css-fonts/Fonts.html

Tue, 16 Jul 2013 15:34:13 +0900

author
John Daggett <jdaggett@mozilla.com>
date
Tue, 16 Jul 2013 15:34:13 +0900
changeset 8699
233e7213b876
parent 8683
7236acf0b724
child 8804
368c6ad02232
permissions
-rw-r--r--

[css3-fonts] fixup Bert's edits and switch back to ED

jdaggett@484 1 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"
jdaggett@484 2 "http://www.w3.org/TR/html4/strict.dtd">
jdaggett@484 3
jdaggett@484 4 <html lang=en>
jdaggett@484 5 <head><meta content="text/html;charset=utf-8" http-equiv=Content-Type>
jdaggett@484 6
jdaggett@1244 7 <title>CSS Fonts Module Level 3</title>
jdaggett@484 8 <!--
jdaggett@484 9 FIXME when publishing: copy the current default.css and link to
jdaggett@484 10 "default.css" rather than "../default.css"
jdaggett@484 11 -->
jdaggett@484 12 <link href="../default.css" rel=stylesheet type="text/css">
jdaggett@8699 13 <link href="../csslogo.ico" rel="shortcut icon" type="image/x-icon">
jdaggett@4546 14 <!-- I'm just experimenting here, don't get your bee in a bonnet -->
jdaggett@4546 15 <script src="http://use.typekit.com/xon2bky.js"
jdaggett@4546 16 type="text/javascript"></script>
jdaggett@4546 17 <script type="text/javascript">try{Typekit.load();}catch(e){}</script>
jdaggett@484 18
jdaggett@497 19 <style type="text/css">
jdaggett@4546 20
jdaggett@4547 21 body, th, td, h1, h2, h3, h4, h5, h6 {
jdaggett@4547 22 font-family: "myriad-pro", sans-serif !important;
jdaggett@4547 23 }
jdaggett@8277 24
jdaggett@524 25 body {
jdaggett@524 26 padding: 2em 70px 2em 70px;
jdaggett@524 27 }
jdaggett@4546 28
jdaggett@497 29 p + p, p.mtb {
jdaggett@497 30 margin-top: 0.8em;
jdaggett@497 31 text-indent: 0px;
jdaggett@497 32 }
jdaggett@6651 33
jdaggett@6651 34 #bolderlighter {
jdaggett@6651 35 width: 40%;
jdaggett@6651 36 }
jdaggett@6651 37
jdaggett@6651 38 #bolderlighter th {
jdaggett@6651 39 text-align: center;
jdaggett@6651 40 }
jdaggett@8277 41
jdaggett@7103 42 #fontformats td, #eventhandlers td, #fontformats th, #eventhandlers th {
jdaggett@1244 43 padding-right: 2em;
jdaggett@512 44 text-align: left;
jdaggett@512 45 }
jdaggett@8277 46
jdaggett@518 47 dd {
jdaggett@518 48 margin-bottom: 1em;
jdaggett@514 49 }
jdaggett@8277 50
jdaggett@516 51 #authors dd {
jdaggett@516 52 margin-bottom: 0;
jdaggett@516 53 }
jdaggett@8277 54
jdaggett@531 55 #fontstylematchingalg {
jdaggett@531 56 list-style-type: lower-alpha;
jdaggett@531 57 }
jdaggett@8277 58
jdaggett@531 59 #fontmatchingalg ul, #fontmatchingalg ol {
jdaggett@531 60 margin-top: 0.8em;
jdaggett@531 61 }
jdaggett@8277 62
jdaggett@531 63 #fontmatchingalg li + li {
jdaggett@531 64 margin-top: 0.8em;
jdaggett@531 65 }
jdaggett@8277 66
jdaggett@531 67 div.example {
jdaggett@531 68 padding: 1em;
jdaggett@531 69 margin-top: 1em;
jdaggett@531 70 }
jdaggett@531 71
jdaggett@531 72 div.example + div.example {
jdaggett@531 73 margin-top: 2em;
jdaggett@531 74 }
jdaggett@8277 75
jdaggett@531 76 div.figure {
jdaggett@531 77 page-break-inside: avoid;
jdaggett@531 78 }
jdaggett@1244 79
jdaggett@1662 80 pre.prod { white-space: pre-wrap; margin: 1em 0 1em 2em }
jdaggett@8277 81
jdaggett@8277 82 div.featex {
jdaggett@1662 83 width: 700px;
jdaggett@1662 84 }
jdaggett@8277 85
jdaggett@1662 86 div.featex img {
jdaggett@1662 87 margin: auto;
jdaggett@1662 88 display: block;
jdaggett@1662 89 }
jdaggett@6436 90
jdaggett@6436 91 span.tag {
jdaggett@6436 92 font-family: monospace;
jdaggett@6436 93 font-size: 120%;
jdaggett@6436 94 }
jdaggett@6648 95
jdaggett@6701 96 ol ol {
jdaggett@6701 97 list-style-type: lower-alpha;
jdaggett@6701 98 }
jdaggett@7060 99
jdaggett@7060 100 .idl-code {
jdaggett@7060 101 font-weight: bold;
jdaggett@7060 102 color: #c50;
jdaggett@7060 103 }
jdaggett@497 104 </style>
jdaggett@2556 105 <link href="http://www.w3.org/StyleSheets/TR/W3C-ED.css" rel=stylesheet
jdaggett@2556 106 type="text/css">
peter@8369 107 <script defer=defer
jdaggett@8385 108 src="http://test.csswg.org/harness/annotate.js#CSS3-FONTS_DEV"
jdaggett@8385 109 type="text/javascript"></script>
jdaggett@497 110
jdaggett@484 111 <body>
jdaggett@484 112 <div class=head> <!--begin-logo-->
jdaggett@484 113 <p><a href="http://www.w3.org/"><img alt=W3C height=48
jdaggett@890 114 src="http://www.w3.org/Icons/w3c_home" width=72></a> <!--end-logo-->
jdaggett@890 115
jdaggett@901 116 <h1>CSS Fonts Module Level 3</h1>
jdaggett@901 117
jdaggett@8699 118 <h2 class="no-num no-toc" id=editors-draft-16-july-2013>Editor's Draft 16
jdaggett@8699 119 July 2013</h2>
jdaggett@484 120
jdaggett@516 121 <dl id=authors>
jdaggett@484 122 <dt>This version:
jdaggett@484 123
jdaggett@484 124 <dd><a
jdaggett@8699 125 href="http://dev.w3.org/csswg/css-fonts/">http://dev.w3.org/csswg/css-fonts/</a>
jdaggett@8699 126 <!-- <dd><a href="http://www.w3.org/TR/2013/ED-css-fonts-3-20130716/">http://www.w3.org/TR/2013/ED-css-fonts-3-20130716/</a> -->
jdaggett@8699 127
jdaggett@484 128
jdaggett@484 129 <dt>Latest version:
jdaggett@484 130
jdaggett@484 131 <dd><a
jdaggett@8699 132 href="http://www.w3.org/TR/css-fonts-3/">http://www.w3.org/TR/css-fonts-3/</a>
jdaggett@484 133
jdaggett@890 134 <dt>Latest editor's draft:
jdaggett@890 135
jdaggett@890 136 <dd><a
jdaggett@8031 137 href="http://dev.w3.org/csswg/css-fonts/">http://dev.w3.org/csswg/css-fonts/</a>
jdaggett@7488 138 (<a
jdaggett@8031 139 href="https://dvcs.w3.org/hg/csswg/log/tip/css-fonts/Fonts.html">change
jdaggett@7488 140 log</a>)
jdaggett@890 141
jdaggett@4624 142 <dt>Previous version:
jdaggett@890 143
jdaggett@890 144 <dd><a
jdaggett@8699 145 href="http://www.w3.org/TR/2013/WD-css-fonts-3-20130711/">http://www.w3.org/TR/2013/WD-css-fonts-3-20130711/</a>
jdaggett@4624 146
jdaggett@4624 147 <dt>Issues List:
jdaggett@4624 148
jdaggett@4624 149 <dd><a href="http://www.w3.org/Style/CSS/Tracker/products/18">CSS3 Fonts
jdaggett@4624 150 issues in Tracker</a>
jdaggett@2556 151
jdaggett@2556 152 <dd><a
jdaggett@6648 153 href="https://www.w3.org/Bugs/Public/buglist.cgi?query_format=advanced&amp;product=CSS&amp;component=Fonts&amp;bug_status=NEW&amp;bug_status=ASSIGNED&amp;bug_status=REOPENED">CSS3
jdaggett@4624 154 Fonts issues in Bugzilla</a>
jdaggett@4624 155
jdaggett@8031 156 <dt>Discussion:
jdaggett@8031 157
jdaggett@8031 158 <dd><a
jdaggett@8031 159 href="mailto:www-style@w3.org?subject=%5Bcss-fonts%5D%20feedback">www-style@w3.org</a>
jdaggett@8031 160 with subject line “<kbd>[css-fonts] <var>… message topic
jdaggett@8031 161 …</var></kbd>” (<a
jdaggett@8031 162 href="http://lists.w3.org/Archives/Public/www-style/"
jdaggett@8031 163 rel=discussion>archives</a>)
jdaggett@890 164
jdaggett@890 165 <dt>Editor:
jdaggett@484 166
jdaggett@497 167 <dd><a href="mailto:jdaggett@mozilla.com">John Daggett (Mozilla)</a>
jdaggett@484 168 </dl>
jdaggett@484 169 <!--begin-copyright-->
jdaggett@484 170 <p class=copyright><a
jdaggett@484 171 href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright"
jdaggett@7179 172 rel=license>Copyright</a> © 2013 <a href="http://www.w3.org/"><abbr
jdaggett@5530 173 title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> (<a
jdaggett@5530 174 href="http://www.csail.mit.edu/"><abbr title="Massachusetts Institute of
jdaggett@5530 175 Technology">MIT</abbr></a>, <a href="http://www.ercim.eu/"><abbr
jdaggett@1662 176 title="European Research Consortium for Informatics and
jdaggett@7244 177 Mathematics">ERCIM</abbr></a>, <a href="http://www.keio.ac.jp/">Keio</a>,
jdaggett@7244 178 <a href="http://ev.buaa.edu.cn/">Beihang</a>), All Rights Reserved. W3C
jdaggett@7244 179 <a
jdaggett@484 180 href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>,
jdaggett@484 181 <a
jdaggett@484 182 href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a>
jdaggett@484 183 and <a
jdaggett@484 184 href="http://www.w3.org/Consortium/Legal/copyright-documents">document
jdaggett@484 185 use</a> rules apply.</p>
jdaggett@484 186 <!--end-copyright-->
jdaggett@484 187 <hr title="Separator for header">
jdaggett@484 188 </div>
jdaggett@525 189
jdaggett@484 190 <h2 class="no-num no-toc" id=abstract>Abstract</h2>
jdaggett@484 191
jdaggett@890 192 <p>This CSS3 module describes how font properties are specified and how
jdaggett@890 193 font resources are loaded dynamically. The contents of this specification
jdaggett@1244 194 are a consolidation of content previously divided into <a
jdaggett@3538 195 href="http://www.w3.org/TR/2002/WD-css3-fonts-20020802/">CSS3 Fonts</a>
jdaggett@3538 196 and <a href="http://www.w3.org/TR/2002/WD-css3-webfonts-20020802/">CSS3
jdaggett@7521 197 Web Fonts</a> modules. The description of font load events was moved into
jdaggett@8646 198 the <a href="http://dev.w3.org/csswg/css-font-load-events/">CSS3 Font Load
jdaggett@8646 199 Events</a> module.
jdaggett@484 200
jdaggett@484 201 <h2 class="no-num no-toc" id=status>Status of this document</h2>
jdaggett@484 202 <!--begin-status-->
jdaggett@484 203
jdaggett@484 204 <p>This is a public copy of the editors' draft. It is provided for
jdaggett@484 205 discussion only and may change at any moment. Its publication here does
jdaggett@484 206 not imply endorsement of its contents by W3C. Don't cite this document
jdaggett@484 207 other than as work in progress.
jdaggett@484 208
jdaggett@484 209 <p>The (<a
jdaggett@484 210 href="http://lists.w3.org/Archives/Public/www-style/">archived</a>) public
jdaggett@1662 211 mailing list <a
jdaggett@1662 212 href="mailto:www-style@w3.org?Subject=%5Bcss3-fonts%5D%20PUT%20SUBJECT%20HERE">
jdaggett@1662 213 www-style@w3.org</a> (see <a
jdaggett@1662 214 href="http://www.w3.org/Mail/Request">instructions</a>) is preferred for
jdaggett@1662 215 discussion of this specification. When sending e-mail, please put the text
jdaggett@1662 216 “css3-fonts” in the subject, preferably like this:
jdaggett@1148 217 “[<!---->css3-fonts<!---->] <em>…summary of comment…</em>”
jdaggett@484 218
jdaggett@8031 219 <p>This document was produced by the <a
jdaggett@8031 220 href="http://www.w3.org/Style/CSS/members">CSS Working Group</a> (part of
jdaggett@8031 221 the <a href="http://www.w3.org/Style/">Style Activity</a>).
jdaggett@484 222
jdaggett@484 223 <p>This document was produced by a group operating under the <a
jdaggett@8031 224 href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5 February
jdaggett@8031 225 2004 W3C Patent Policy</a>. W3C maintains a <a
jdaggett@8031 226 href="http://www.w3.org/2004/01/pp-impl/32061/status"
jdaggett@484 227 rel=disclosure>public list of any patent disclosures</a> made in
jdaggett@484 228 connection with the deliverables of the group; that page also includes
jdaggett@484 229 instructions for disclosing a patent. An individual who has actual
jdaggett@484 230 knowledge of a patent which the individual believes contains <a
jdaggett@8031 231 href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential
jdaggett@484 232 Claim(s)</a> must disclose the information in accordance with <a
jdaggett@8031 233 href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section
jdaggett@8031 234 6 of the W3C Patent Policy</a>.</p>
jdaggett@484 235 <!--end-status-->
jdaggett@8385 236
jdaggett@8385 237 <h3 class="no-num no-toc" id=atrisk>Features at risk</h3>
jdaggett@8385 238
jdaggett@8385 239 <p>The following features are at risk and may be removed when exiting CR:
jdaggett@8385 240
jdaggett@8385 241 <ul>
jdaggett@8386 242 <li>fallback handling for text decoration in superscript/subscript variant
jdaggett@8385 243 glyphs (‘<a href="#propdef-font-variant-position"><code
jdaggett@8385 244 class=property>font-variant-position</code></a>’)
jdaggett@8385 245
jdaggett@8385 246 <li>‘<a href="#propdef-font-language-override"><code
jdaggett@8385 247 class=property>font-language-override</code></a>’ property
jdaggett@8385 248 </ul>
jdaggett@8699 249 <!--
jdaggett@8699 250 <p>This draft is a <strong>Last Call Working Draft</strong>.
jdaggett@8699 251 Please send comments to the
jdaggett@8699 252 <a href="http://lists.w3.org/Archives/Public/www-style/">www-style mailing list</a>
jdaggett@8699 253 as described above. The <strong>deadline for comments</strong>
jdaggett@8699 254 is six weeks after the date of publication in the header, 22 August 2013.</p>
jdaggett@8699 255 -->
jdaggett@2472 256
jdaggett@484 257 <h2 class="no-num no-toc" id=contents>Table of contents</h2>
jdaggett@484 258 <!--begin-toc-->
jdaggett@484 259
jdaggett@484 260 <ul class=toc>
jdaggett@890 261 <li><a href="#introduction"><span class=secno>1 </span>Introduction</a>
jdaggett@890 262
jdaggett@1244 263 <li><a href="#typography-background"><span class=secno>2 </span>Typography
jdaggett@545 264 Background</a>
jdaggett@545 265
jdaggett@6699 266 <li><a href="#basic-font-props"><span class=secno>3 </span>Basic Font
jdaggett@6699 267 Properties</a>
jdaggett@484 268 <ul class=toc>
jdaggett@1662 269 <li><a href="#font-family-prop"><span class=secno>3.1 </span>Font
jdaggett@1662 270 family: the font-family property</a>
jdaggett@514 271 <ul class=toc>
jdaggett@1244 272 <li><a href="#generic-font-families"><span class=secno>3.1.1
jdaggett@1244 273 </span>Generic font families</a>
jdaggett@514 274 </ul>
jdaggett@484 275
jdaggett@1662 276 <li><a href="#font-weight-prop"><span class=secno>3.2 </span>Font
jdaggett@1662 277 weight: the font-weight property</a>
jdaggett@1662 278
jdaggett@1662 279 <li><a href="#font-stretch-prop"><span class=secno>3.3 </span>Font
jdaggett@1662 280 width: the font-stretch property</a>
jdaggett@1662 281
jdaggett@1662 282 <li><a href="#font-style-prop"><span class=secno>3.4 </span>Font style:
jdaggett@1662 283 the font-style property</a>
jdaggett@1662 284
jdaggett@1662 285 <li><a href="#font-size-prop"><span class=secno>3.5 </span>Font size:
jdaggett@1662 286 the font-size property</a>
jdaggett@1662 287
jdaggett@1662 288 <li><a href="#font-size-adjust-prop"><span class=secno>3.6
jdaggett@1662 289 </span>Relative sizing: the font-size-adjust property</a>
jdaggett@1662 290
jdaggett@1662 291 <li><a href="#font-prop"><span class=secno>3.7 </span>Shorthand font
jdaggett@1662 292 property: the font property</a>
jdaggett@2457 293
jdaggett@2487 294 <li><a href="#font-synthesis-prop"><span class=secno>3.8
jdaggett@2487 295 </span>Controlling synthetic faces: the font-synthesis property</a>
jdaggett@484 296 </ul>
jdaggett@484 297
jdaggett@890 298 <li><a href="#font-resources"><span class=secno>4 </span>Font
jdaggett@6699 299 Resources</a>
jdaggett@512 300 <ul class=toc>
jdaggett@1662 301 <li><a href="#font-face-rule"><span class=secno>4.1 </span>The
jdaggett@7096 302 <code>@font-face</code> rule</a>
jdaggett@1244 303
jdaggett@1662 304 <li><a href="#font-family-desc"><span class=secno>4.2 </span>Font
jdaggett@1662 305 family: the font-family descriptor</a>
jdaggett@1662 306
jdaggett@1662 307 <li><a href="#src-desc"><span class=secno>4.3 </span>Font reference: the
jdaggett@1662 308 src descriptor</a>
jdaggett@1662 309
jdaggett@1662 310 <li><a href="#font-prop-desc"><span class=secno>4.4 </span>Font property
jdaggett@1662 311 descriptors: the font-style, font-weight, font-stretch descriptors</a>
jdaggett@1662 312
jdaggett@1662 313 <li><a href="#unicode-range-desc"><span class=secno>4.5 </span>Character
jdaggett@1662 314 range: the unicode-range descriptor</a>
jdaggett@1662 315
jdaggett@8225 316 <li><a href="#composite-fonts"><span class=secno>4.6 </span>Using
jdaggett@8225 317 character ranges to define composite fonts</a>
jdaggett@8225 318
jdaggett@8225 319 <li><a href="#font-rend-desc"><span class=secno>4.7 </span>Font
jdaggett@1732 320 features: the font-variant and font-feature-settings descriptors</a>
jdaggett@2563 321
jdaggett@8225 322 <li><a href="#font-face-loading"><span class=secno>4.8 </span>Font
jdaggett@2563 323 loading guidelines</a>
jdaggett@2737 324
jdaggett@8225 325 <li><a href="#same-origin-restriction"><span class=secno>4.9
jdaggett@2737 326 </span>Same-origin restriction for fonts</a>
jdaggett@2740 327 <ul class=toc>
jdaggett@8225 328 <li><a href="#default-same-origin-restriction"><span class=secno>4.9.1
jdaggett@2740 329 </span>Default same-origin restriction</a>
jdaggett@2740 330
jdaggett@2740 331 <li><a href="#allowing-cross-origin-font-loading"><span
jdaggett@8225 332 class=secno>4.9.2 </span>Allowing cross-origin font loading</a>
jdaggett@2740 333 </ul>
jdaggett@512 334 </ul>
jdaggett@484 335
jdaggett@1244 336 <li><a href="#font-matching-algorithm"><span class=secno>5 </span>Font
jdaggett@6699 337 Matching Algorithm</a>
jdaggett@2457 338 <ul class=toc>
jdaggett@7309 339 <li><a href="#font-family-casing"><span class=secno>5.1 </span>Case
jdaggett@7309 340 sensitivity of font family names</a>
jdaggett@7309 341
jdaggett@7309 342 <li><a href="#font-style-matching"><span class=secno>5.2 </span>Matching
jdaggett@2457 343 font styles</a>
jdaggett@2457 344
jdaggett@7309 345 <li><a href="#cluster-matching"><span class=secno>5.3 </span>Cluster
jdaggett@6701 346 matching</a>
jdaggett@6701 347
jdaggett@7309 348 <li><a href="#char-handling-issues"><span class=secno>5.4
jdaggett@2457 349 </span>Character handling issues</a>
jdaggett@2509 350
jdaggett@7309 351 <li><a href="#font-matching-changes"><span class=secno>5.5 </span>Font
jdaggett@2509 352 matching changes since CSS 2.1</a>
jdaggett@6701 353
jdaggett@7309 354 <li><a href="#font-matching-examples"><span class=secno>5.6 </span>Font
jdaggett@6701 355 matching examples</a>
jdaggett@2457 356 </ul>
jdaggett@1244 357
jdaggett@6699 358 <li><a href="#font-rend-props"><span class=secno>6 </span>Font Feature
jdaggett@6699 359 Properties</a>
jdaggett@1662 360 <ul class=toc>
jdaggett@1856 361 <li><a href="#glyph-selection-positioning"><span class=secno>6.1
jdaggett@1856 362 </span>Glyph selection and positioning</a>
jdaggett@1856 363
jdaggett@1856 364 <li><a href="#language-specific-support"><span class=secno>6.2
jdaggett@1856 365 </span>Language-specific display</a>
jdaggett@1856 366
jdaggett@1856 367 <li><a href="#font-kerning-prop"><span class=secno>6.3 </span>Kerning:
jdaggett@1662 368 the font-kerning property</a>
jdaggett@1662 369
jdaggett@6176 370 <li><a href="#font-variant-ligatures-prop"><span class=secno>6.4
jdaggett@6176 371 </span>Ligatures: the font-variant-ligatures property</a>
jdaggett@6176 372
jdaggett@6176 373 <li><a href="#font-variant-position-prop"><span class=secno>6.5
jdaggett@3638 374 </span>Subscript and superscript forms: the font-variant-position
jdaggett@3638 375 property</a>
jdaggett@1856 376
jdaggett@2118 377 <li><a href="#font-variant-caps-prop"><span class=secno>6.6
jdaggett@2118 378 </span>Capitalization: the font-variant-caps property</a>
jdaggett@2118 379
jdaggett@2118 380 <li><a href="#font-variant-numeric-prop"><span class=secno>6.7
jdaggett@2118 381 </span>Numerical formatting: the font-variant-numeric property</a>
jdaggett@2118 382
jdaggett@2118 383 <li><a href="#font-variant-alternates-prop"><span class=secno>6.8
jdaggett@1662 384 </span>Alternates and swashes: the font-variant-alternates property</a>
jdaggett@1662 385
jdaggett@1662 386
jdaggett@2472 387 <li><a href="#font-feature-values"><span class=secno>6.9 </span>Defining
jdaggett@7096 388 font specific alternates: the <code>@font-feature-values</code>
jdaggett@7096 389 rule</a>
jdaggett@8356 390 <ul class=toc>
jdaggett@8356 391 <li><a href="#basic-syntax"><span class=secno>6.9.1 </span>Basic
jdaggett@8356 392 syntax</a>
jdaggett@8356 393
jdaggett@8356 394 <li><a href="#multi-valued-feature-value-definitions"><span
jdaggett@8356 395 class=secno>6.9.2 </span>Multi-valued feature value definitions</a>
jdaggett@8356 396 </ul>
jdaggett@2118 397
jdaggett@2118 398 <li><a href="#font-variant-east-asian-prop"><span class=secno>6.10
jdaggett@1662 399 </span>East Asian text rendering: the font-variant-east-asian
jdaggett@1662 400 property</a>
jdaggett@1662 401
jdaggett@2118 402 <li><a href="#font-variant-prop"><span class=secno>6.11 </span>Overall
jdaggett@1662 403 shorthand for font rendering: the font-variant property</a>
jdaggett@1662 404
jdaggett@2118 405 <li><a href="#font-feature-settings-prop"><span class=secno>6.12
jdaggett@2509 406 </span>Low-level font feature settings control: the
jdaggett@2509 407 font-feature-settings property</a>
jdaggett@1662 408
jdaggett@2118 409 <li><a href="#font-language-override-prop"><span class=secno>6.13
jdaggett@1732 410 </span>Font language override: the font-language-override property</a>
jdaggett@1662 411 </ul>
jdaggett@1662 412
jdaggett@6176 413 <li><a href="#font-feature-resolution"><span class=secno>7 </span>Font
jdaggett@6699 414 Feature Resolution </a>
jdaggett@6699 415 <ul class=toc>
jdaggett@6699 416 <li><a href="#default-features"><span class=secno>7.1 </span>Default
jdaggett@6699 417 features</a>
jdaggett@6699 418
jdaggett@6699 419 <li><a href="#feature-precedence"><span class=secno>7.2 </span>Feature
jdaggett@6699 420 precedence</a>
jdaggett@6699 421
jdaggett@6699 422 <li><a href="#feature-precedence-examples"><span class=secno>7.3
jdaggett@6699 423 </span>Feature precedence examples</a>
jdaggett@6699 424 </ul>
jdaggett@6699 425
jdaggett@7021 426 <li><a href="#object-model"><span class=secno>8 </span>Object Model</a>
jdaggett@7021 427 <ul class=toc>
jdaggett@7021 428 <li><a href="#om-fontface"><span class=secno>8.1 </span>The
jdaggett@7021 429 <code>CSSFontFaceRule</code> interface</a>
jdaggett@7021 430
jdaggett@7021 431 <li><a href="#om-fontfeaturevalues"><span class=secno>8.2 </span>The
jdaggett@7021 432 <code>CSSFontFeatureValuesRule</code> interface</a>
jdaggett@7021 433 </ul>
jdaggett@7021 434
jdaggett@2737 435 <li class=no-num><a href="#platform-props-to-css">Appendix A: Mapping
jdaggett@1662 436 platform font properties to CSS properties</a>
jdaggett@1662 437
jdaggett@2472 438 <li class=no-num><a href="#ch-ch-ch-changes">Changes</a>
jdaggett@2472 439 <ul class=toc>
jdaggett@8699 440 <li class=no-num><a href="#recent-changes"> Changes from the July 2013
jdaggett@8699 441 CSS3 Fonts Last Call Working Draft</a>
jdaggett@2472 442 </ul>
jdaggett@2472 443
jdaggett@529 444 <li class=no-num><a href="#acknowledgments">Acknowledgments</a>
jdaggett@529 445
jdaggett@7242 446 <li class=no-num><a href="#conformance"> Conformance</a>
jdaggett@7242 447 <ul class=toc>
jdaggett@7242 448 <li class=no-num><a href="#conventions"> Document Conventions</a>
jdaggett@7242 449
jdaggett@7242 450 <li class=no-num><a href="#conformance-classes"> Conformance Classes</a>
jdaggett@7242 451
jdaggett@7242 452
jdaggett@7242 453 <li class=no-num><a href="#partial"> Partial Implementations</a>
jdaggett@7242 454
jdaggett@7242 455 <li class=no-num><a href="#experimental"> Experimental
jdaggett@7242 456 Implementations</a>
jdaggett@7242 457
jdaggett@7242 458 <li class=no-num><a href="#testing"> Non-Experimental
jdaggett@7242 459 Implementations</a>
jdaggett@7242 460 </ul>
jdaggett@7242 461
jdaggett@484 462 <li class=no-num><a href="#references">References</a>
jdaggett@484 463 <ul class=toc>
jdaggett@1662 464 <li class=no-num><a href="#normative-references">Normative
jdaggett@1662 465 References</a>
jdaggett@1662 466
jdaggett@1662 467 <li class=no-num><a href="#other-references">Other References</a>
jdaggett@484 468 </ul>
jdaggett@484 469
jdaggett@484 470 <li class=no-num><a href="#index">Index</a>
jdaggett@484 471
jdaggett@484 472 <li class=no-num><a href="#property-index">Property index</a>
jdaggett@484 473 </ul>
jdaggett@484 474 <!--end-toc-->
jdaggett@484 475
jdaggett@890 476 <h2 id=introduction><span class=secno>1 </span>Introduction</h2>
jdaggett@545 477
jdaggett@1148 478 <p>A font provides a resource containing the visual representation of
jdaggett@1662 479 characters. At the simplest level it contains information that maps
jdaggett@1662 480 character codes to shapes (called glyphs) that represent these characters.
jdaggett@1662 481 Fonts sharing a common design style are commonly grouped into font
jdaggett@1662 482 families classified by a set of standard font properties. Within a family,
jdaggett@1662 483 the shape displayed for a given character can vary by stroke weight, slant
jdaggett@7311 484 or relative width, among others. An individual font face is described by a
jdaggett@1662 485 unique combination of these properties. For a given range of text, CSS
jdaggett@1662 486 font properties are used to select a font family and a specific font face
jdaggett@1662 487 within that family to be used when rendering that text. As a simple
jdaggett@1662 488 example, to use the bold form of Helvetica one could use:
jdaggett@1148 489
jdaggett@8277 490 <pre>body {
jdaggett@8277 491 font-family: Helvetica;
jdaggett@8277 492 font-weight: bold;
jdaggett@1148 493 }</pre>
jdaggett@1148 494
jdaggett@7311 495 <p>Font resources may be installed locally on the system on which a user
jdaggett@7311 496 agent is running or downloadable. For local font resources descriptive
jdaggett@1148 497 information can be obtained directly from the font resource. For
jdaggett@1148 498 downloadable font resources (sometimes referred to as web fonts), the
jdaggett@1148 499 descriptive information is included with the reference to the font
jdaggett@1148 500 resource.
jdaggett@1148 501
jdaggett@1148 502 <p>Families of fonts typically don't contain a single face for each
jdaggett@1148 503 possible variation of font properties. The CSS font selection mechanism
jdaggett@7311 504 describes how to match a given set of CSS font properties to a single font
jdaggett@1148 505 face.
jdaggett@890 506
jdaggett@1244 507 <h2 id=typography-background><span class=secno>2 </span>Typography
jdaggett@1244 508 Background</h2>
jdaggett@890 509
jdaggett@7311 510 <p><em>This section is non-normative.</em>
jdaggett@7311 511
jdaggett@7311 512 <p> Typographic traditions vary across the globe, so there is no unique way
jdaggett@890 513 to classify all fonts across languages and cultures. For even common Latin
jdaggett@890 514 letters, wide variations are possible:
jdaggett@497 515
jdaggett@1150 516 <div class=figure><img alt="variations in glyphs for a single character"
jdaggett@1150 517 src=aaaaaa.png>
jdaggett@890 518 <p class=caption>One character, many glyph variations
jdaggett@498 519 </div>
jdaggett@497 520
jdaggett@497 521 <p>Differences in the anatomy of letterforms is one way to distinguish
jdaggett@497 522 fonts. For Latin fonts, flourishes at the ends of a character's main
jdaggett@497 523 strokes, or serifs, can distinguish a font from those without. Similar
jdaggett@534 524 comparisons exist in non-Latin fonts between fonts with tapered strokes
jdaggett@534 525 and those using primarily uniform strokes:
jdaggett@497 526
jdaggett@1150 527 <div class=figure><img alt="serif vs. non-serifs" src=serifvssansserif.png>
jdaggett@890 528 <p class=caption>Letterforms with and without serifs
jdaggett@534 529 </div>
jdaggett@534 530
jdaggett@1150 531 <div class=figure><img alt="serif vs. non-serifs for japanese"
jdaggett@1150 532 src=minchovsgothic.png>
jdaggett@890 533 <p class=caption>Similar groupings for Japanese typefaces
jdaggett@498 534 </div>
jdaggett@497 535
jdaggett@497 536 <p>Fonts contain letterforms and the data needed to map characters to these
jdaggett@7311 537 letterforms. Often this may be a simple one-to-one mapping, but more
jdaggett@497 538 complex mappings are also possible. The use of combining diacritic marks
jdaggett@497 539 creates many variations for an underlying letterform:
jdaggett@497 540
jdaggett@1150 541 <div class=figure><img alt="diacritic marks" src=aaaaaa-diacritics.png>
jdaggett@890 542 <p class=caption>Variations with diacritic marks
jdaggett@498 543 </div>
jdaggett@525 544
jdaggett@497 545 <p>A sequence of characters can be represented by a single glyph known as a
jdaggett@497 546 ligature:
jdaggett@497 547
jdaggett@1150 548 <div class=figure><img alt="example of a fi ligature"
jdaggett@1150 549 src=final-ligature.png>
jdaggett@890 550 <p class=caption>Ligature example
jdaggett@498 551 </div>
jdaggett@497 552
jdaggett@7311 553 <p>Visual transformations based on textual context are often stylistic
jdaggett@7311 554 option in European languages. They are required to correctly render
jdaggett@7311 555 languages like Arabic, the lam and alef characters below <em>must</em> be
jdaggett@7311 556 combined when they exist in sequence:
jdaggett@497 557
jdaggett@1150 558 <div class=figure><img alt="lam alef ligature" src=lamaleflig.png>
jdaggett@890 559 <p class=caption>Required Arabic ligature
jdaggett@498 560 </div>
jdaggett@497 561
jdaggett@498 562 <p>The relative complexity of these shaping transformations requires
jdaggett@498 563 additional data within the font.
jdaggett@497 564
jdaggett@497 565 <p>Sets of font faces with various stylistic variations are often grouped
jdaggett@512 566 together into font families. In the simplest case a regular face is
jdaggett@7311 567 supplemented with bold and italic faces, but much more extensive groupings
jdaggett@7311 568 are possible. Variations in the thickness of letterform strokes, the <dfn
jdaggett@7311 569 id=weight>weight</dfn>, and the overall proportions of the letterform, the
jdaggett@7311 570 <dfn id=width>width</dfn>, are most common. In the example below, each
jdaggett@7311 571 letter uses a different font face within the Univers font family. The
jdaggett@7311 572 width used increases from top to bottom and the weight increases from left
jdaggett@7311 573 to right:
jdaggett@497 574
jdaggett@1150 575 <div class=figure><img alt="various width and weight variations within a
jdaggett@1150 576 single family" src=weightwidthvariations.png>
jdaggett@890 577 <p class=caption>Weight and width variations within a single font family
jdaggett@498 578 </div>
jdaggett@497 579
jdaggett@545 580 <p>Creating fonts that support multiple scripts is a difficult task;
jdaggett@1148 581 designers need to understand the cultural traditions surrounding the use
jdaggett@1148 582 of type in different scripts and come up with letterforms that somehow
jdaggett@1148 583 share a common theme. Many languages often share a common script and each
jdaggett@7311 584 of these languages may have noticeable stylistic differences. For example,
jdaggett@7311 585 the Arabic script is shared by Persian and Urdu and Cyrillic is used with
jdaggett@7311 586 many languages, not just Russian.
jdaggett@518 587
jdaggett@8225 588 <p>The <a href="#character-map"><em>character map</em></a> of a font
jdaggett@8225 589 defines the mapping of characters to glyphs for that font. If a document
jdaggett@8225 590 contains characters not supported by the <a href="#character-map"><em
jdaggett@8225 591 title="character map">character maps</em></a> of the fonts contained in a
jdaggett@8363 592 font family list, a user agent may use a <a
jdaggett@8363 593 href="#system-font-fallback"><em>system font fallback</em></a> procedure
jdaggett@8363 594 to locate an appropriate font that does. If no appropriate font can be
jdaggett@8363 595 found, some form of "missing glyph" character will be rendered by the user
jdaggett@8363 596 agent. System fallback can occur when the specified list of font families
jdaggett@8363 597 does not include a font that supports a given character.
jdaggett@8225 598
jdaggett@8225 599 <p>Although the <a href="#character-map"><em>character map</em></a> of a
jdaggett@8225 600 font maps a given character to a glyph for that character, modern font
jdaggett@8225 601 technologies such as OpenType and AAT (Apple Advanced Typography) provide
jdaggett@8225 602 ways of mapping a character to different glyphs based upon feature
jdaggett@8225 603 settings. Fonts in these formats allow these features to be embedded in
jdaggett@8225 604 the font itself and controlled by applications. Common typographic
jdaggett@8225 605 features which can be specified this way include ligatures, swashes,
jdaggett@8225 606 contextual alternates, proportional and tabular figures, and automatic
jdaggett@8225 607 fractions, to list just a few. For a visual overview of OpenType features,
jdaggett@8225 608 see the <a href="#OPENTYPE-FONT-GUIDE"
jdaggett@6659 609 rel=biblioentry>[OPENTYPE-FONT-GUIDE]<!--{{OPENTYPE-FONT-GUIDE}}--></a>.
jdaggett@1662 610
jdaggett@6699 611 <h2 id=basic-font-props><span class=secno>3 </span>Basic Font Properties</h2>
jdaggett@512 612
jdaggett@512 613 <p>The particular font face used to render a character is determined by the
jdaggett@515 614 font family and other font properties that apply to a given element. This
jdaggett@515 615 structure allows settings to be varied independent of each other.</p>
jdaggett@512 616 <!-- prop: font-family -->
jdaggett@484 617
jdaggett@1662 618 <h3 id=font-family-prop><span class=secno>3.1 </span>Font family: the <a
jdaggett@1662 619 href="#propdef-font-family">font-family</a> property</h3>
jdaggett@1662 620
jdaggett@8225 621 <table class=propdef id=namefont-familyvalue-ltfamily-namegt-ltg>
jdaggett@484 622 <tbody>
jdaggett@484 623 <tr>
jdaggett@484 624 <td>Name:
jdaggett@484 625
jdaggett@8278 626 <td><dfn id=propdef-font-family
jdaggett@8278 627 title="font-family!!property">font-family</dfn>
jdaggett@484 628
jdaggett@484 629 <tr>
jdaggett@484 630 <td>Value:
jdaggett@484 631
jdaggett@8225 632 <td>[ <a href="#family-name-value"><var>&lt;family-name&gt;</var></a> |
jdaggett@8225 633 <a href="#generic-family-value"><var>&lt;generic-family&gt;</var></a> ]
jdaggett@8225 634 #
jdaggett@484 635
jdaggett@484 636 <tr>
jdaggett@484 637 <td>Initial:
jdaggett@484 638
jdaggett@484 639 <td>depends on user agent
jdaggett@484 640
jdaggett@484 641 <tr>
jdaggett@484 642 <td>Applies to:
jdaggett@484 643
jdaggett@484 644 <td>all elements
jdaggett@484 645
jdaggett@484 646 <tr>
jdaggett@484 647 <td>Inherited:
jdaggett@484 648
jdaggett@484 649 <td>yes
jdaggett@484 650
jdaggett@484 651 <tr>
jdaggett@484 652 <td>Percentages:
jdaggett@484 653
jdaggett@484 654 <td>N/A
jdaggett@484 655
jdaggett@484 656 <tr>
jdaggett@484 657 <td>Media:
jdaggett@484 658
jdaggett@484 659 <td>visual
jdaggett@484 660
jdaggett@484 661 <tr>
jdaggett@1148 662 <td>Computed value:
jdaggett@484 663
jdaggett@484 664 <td>as specified
jdaggett@7377 665
jdaggett@7377 666 <tr>
jdaggett@7377 667 <td>Animatable:
jdaggett@7377 668
jdaggett@7377 669 <td>no
jdaggett@484 670 </table>
jdaggett@484 671
jdaggett@514 672 <p>This property specifies a prioritized list of font family names or
jdaggett@6694 673 generic family names. A font family defines a set of faces that vary in
jdaggett@6694 674 weight, width or slope. CSS uses the combination of a family name with
jdaggett@6694 675 other style attributes to select an individual face. Using this selection
jdaggett@6694 676 mechanism, rather than selecting a face via the style name as is often
jdaggett@6694 677 done in design applications, allows some degree of regularity in textual
jdaggett@6694 678 display when fallback occurs.
jdaggett@6694 679
jdaggett@6694 680 <p class=note>Designers should note that the CSS definition of font
jdaggett@6694 681 attributes used for selection are explicitly not intended to define a font
jdaggett@6694 682 taxonomy. A type designer's idea of a family may often extend to a set of
jdaggett@6694 683 faces that vary along axes other than just the standard axes of weight,
jdaggett@6694 684 width and slope. A family may extend to include both a set of serif faces
jdaggett@6694 685 and a set of sans-serif faces or vary along axes that are unique to that
jdaggett@6694 686 family. The CSS font selection mechanism merely provides a way to
jdaggett@6694 687 determine the “closest” substitute when substitution is necessary.
jdaggett@6694 688
jdaggett@6694 689 <p>Unlike other CSS properties, component values are a comma-separated list
jdaggett@6694 690 indicating alternatives. A user agent iterates through the list of family
jdaggett@6694 691 names until it matches an available font that contains a glyph for the
jdaggett@6694 692 character to be rendered. This allows for differences in available fonts
jdaggett@6694 693 across platforms and for differences in the range of characters supported
jdaggett@6694 694 by individual fonts.
jdaggett@514 695
jdaggett@514 696 <p>A font family name only specifies a name given to a set of font faces,
jdaggett@8177 697 it does not specify an individual face. For example, given the
jdaggett@8177 698 availability of the fonts below, Futura would match but Futura Medium
jdaggett@8177 699 would not:
jdaggett@514 700
jdaggett@1150 701 <div class=figure><img alt="family and face names"
jdaggett@1150 702 src=familyvsfacename.png>
jdaggett@890 703 <p class=caption>Family and individual face names
jdaggett@514 704 </div>
jdaggett@514 705
jdaggett@514 706 <p>Consider the example below:
jdaggett@512 707
jdaggett@512 708 <div class=example>
jdaggett@8277 709 <pre>body {
jdaggett@8277 710 font-family: Helvetica, Verdana, sans-serif;
jdaggett@514 711 }</pre>
jdaggett@1758 712
jdaggett@1758 713 <p>If Helvetica is available it will be used when rendering. If neither
jdaggett@1758 714 Helvetica nor Verdana is present, then the user-agent-defined sans serif
jdaggett@1758 715 font will be used.</p>
jdaggett@512 716 </div>
jdaggett@512 717
jdaggett@514 718 <p>There are two types of font family names:
jdaggett@512 719
jdaggett@512 720 <dl>
jdaggett@8225 721 <dt><dfn id=family-name-value><var>&lt;family-name&gt;</var></dfn>
jdaggett@514 722
jdaggett@514 723 <dd>The name of a font family of choice such as Helvetica or Verdana in
jdaggett@2457 724 the previous example.
jdaggett@514 725
jdaggett@8225 726 <dt><dfn id=generic-family-value><var>&lt;generic-family&gt;</var></dfn>
jdaggett@514 727
jdaggett@4624 728 <dd> The following generic family keywords are defined: ‘<a
jdaggett@4624 729 href="#serif"><code class=property>serif</code></a>’, ‘<a
jdaggett@4624 730 href="#sans-serif"><code class=property>sans-serif</code></a>’, ‘<a
jdaggett@4624 731 href="#cursive"><code class=property>cursive</code></a>’, ‘<a
jdaggett@4624 732 href="#fantasy"><code class=property>fantasy</code></a>’, and ‘<a
jdaggett@4624 733 href="#monospace"><code class=property>monospace</code></a>’. These
jdaggett@1148 734 keywords can be used as a general fallback mechanism when an author's
jdaggett@1758 735 desired font choices are not available. As keywords, they must not be
jdaggett@1148 736 quoted. Authors are encouraged to append a generic font family as a last
jdaggett@1148 737 alternative for improved robustness.
jdaggett@512 738 </dl>
jdaggett@512 739
jdaggett@8272 740 <p>Font family names other than generic families must either be given
jdaggett@8272 741 quoted as <a
jdaggett@8699 742 href="http://www.w3.org/TR/CSS21/syndata.html#strings">strings,</a> or
jdaggett@8699 743 unquoted as a sequence of one or more <a
bert@8683 744 href="http://www.w3.org/TR/CSS21/syndata.html#value-def-identifier">identifiers.</a>
jdaggett@2457 745 This means most punctuation characters and digits at the start of each
jdaggett@2457 746 token must be escaped in unquoted font family names.
jdaggett@2457 747
jdaggett@7377 748 <p>To illustrate this, the following declarations are invalid:
jdaggett@2457 749
jdaggett@2457 750 <pre>
jdaggett@2457 751 font-family: Red/Black, sans-serif;
jdaggett@2457 752 font-family: "Lucida" Grande, sans-serif;
jdaggett@2457 753 font-family: Ahem!, sans-serif;
jdaggett@2457 754 font-family: test@foo, sans-serif;
jdaggett@2457 755 font-family: #POUND, sans-serif;
jdaggett@2457 756 font-family: Hawaii 5-0, sans-serif;
jdaggett@2457 757 </pre>
jdaggett@2457 758
jdaggett@2457 759 <p>If a sequence of identifiers is given as a font family name, the
jdaggett@2457 760 computed value is the name converted to a string by joining all the
jdaggett@2457 761 identifiers in the sequence by single spaces.
jdaggett@2457 762
jdaggett@2457 763 <p>To avoid mistakes in escaping, it is recommended to quote font family
jdaggett@2457 764 names that contain white space, digits, or punctuation characters other
jdaggett@2457 765 than hyphens:
jdaggett@2457 766
jdaggett@2457 767 <pre>
jdaggett@2457 768 body { font-family: "New Century Schoolbook", serif }
jdaggett@2457 769
jdaggett@2457 770 &lt;BODY STYLE="font-family: '21st Century', fantasy">
jdaggett@2457 771 </pre>
jdaggett@2457 772
jdaggett@2457 773 <p>Font family <em>names</em> that happen to be the same as a keyword value
jdaggett@4624 774 (‘<code class=property>inherit</code>’, ‘<a href="#serif"><code
jdaggett@4624 775 class=property>serif</code></a>’, ‘<a href="#sans-serif"><code
jdaggett@4624 776 class=property>sans-serif</code></a>’, ‘<a href="#monospace"><code
jdaggett@4624 777 class=property>monospace</code></a>’, ‘<a href="#fantasy"><code
jdaggett@4624 778 class=property>fantasy</code></a>’, and ‘<a href="#cursive"><code
jdaggett@4624 779 class=property>cursive</code></a>’) must be quoted to prevent confusion
jdaggett@2457 780 with the keywords with the same names. The keywords ‘<code
jdaggett@2457 781 class=property>initial</code>’ and ‘<code
jdaggett@2457 782 class=property>default</code>’ are reserved for future use and must also
jdaggett@2457 783 be quoted when used as font names. UAs must not consider these keywords as
jdaggett@8225 784 matching the <a
jdaggett@8225 785 href="#family-name-value"><var>&lt;family-name&gt;</var></a> type.
jdaggett@2457 786
jdaggett@6694 787 <p>The precise way a set of fonts are grouped into font families varies
jdaggett@6694 788 depending upon the platform font management API's. The Windows GDI API
jdaggett@6694 789 only allows four faces to be grouped into a family while the DirectWrite
jdaggett@6694 790 API and API's on OSX and other platforms support font families with a
jdaggett@6695 791 variety of weights, widths and slopes (see <a
jdaggett@6694 792 href="#platform-props-to-css">Appendix A</a> for more details).
jdaggett@6694 793
jdaggett@2457 794 <p>Some font formats allow fonts to carry multiple localizations of the
jdaggett@2457 795 family name. User agents must recognize and correctly match all of these
jdaggett@2457 796 names independent of the underlying platform localization, system API used
jdaggett@2457 797 or document encoding:
jdaggett@2457 798
jdaggett@2457 799 <div class=figure><img alt="examples of localized family names"
jdaggett@2457 800 src=localizedfamilynames.png>
jdaggett@2457 801 <p class=caption>Localized family names
jdaggett@2457 802 </div>
jdaggett@2457 803
jdaggett@1244 804 <h4 id=generic-font-families><span class=secno>3.1.1 </span>Generic font
jdaggett@1244 805 families</h4>
jdaggett@514 806
jdaggett@518 807 <p>All five generic font families are defined to exist in all CSS
jdaggett@518 808 implementations (they need not necessarily map to five distinct actual
jdaggett@518 809 fonts). User agents should provide reasonable default choices for the
jdaggett@518 810 generic font families, which express the characteristics of each family as
jdaggett@518 811 well as possible within the limits allowed by the underlying technology.
jdaggett@518 812 User agents are encouraged to allow users to select alternative choices
jdaggett@514 813 for the generic fonts.
jdaggett@514 814
jdaggett@890 815 <h5 class="no-num no-toc"> <span class=index-def id=serif0 title="serif,
jdaggett@890 816 definition of"><a name=serif-def><dfn id=serif>serif</dfn></a></span></h5>
jdaggett@514 817
jdaggett@8178 818 <p>Serif fonts represent the formal text style for a script. This often
jdaggett@8178 819 means but is not limited to glyphs that have finishing strokes, flared or
jdaggett@8178 820 tapering ends, or have actual serifed endings (including slab serifs).
jdaggett@8178 821 Serif fonts are typically proportionately-spaced. They often display a
jdaggett@8178 822 greater variation between thick and thin strokes than fonts from the ‘<a
jdaggett@8178 823 href="#sans-serif"><code class=property>sans-serif</code></a>’ generic
jdaggett@8178 824 font family. CSS uses the term ‘<a href="#serif"><code
jdaggett@8178 825 class=property>serif</code></a>’ to apply to a font for any script,
jdaggett@8178 826 although other names may be more familiar for particular scripts, such as
jdaggett@8178 827 Mincho (Japanese), Sung, Song or Kai (Chinese), Batang (Korean). For
jdaggett@8178 828 Arabic, the Naskh style would correspond to ‘<a href="#serif"><code
jdaggett@8178 829 class=property>serif</code></a>’ more due to its typographic role rather
jdaggett@8178 830 than its actual design style. Any font that is so described may be used to
jdaggett@4624 831 represent the generic ‘<a href="#serif"><code
jdaggett@4624 832 class=property>serif</code></a>’ family.
jdaggett@514 833
jdaggett@1150 834 <div class=figure><img alt="sample serif fonts" src=serifexamples.png>
jdaggett@890 835 <p class=caption>Sample serif fonts
jdaggett@514 836 </div>
jdaggett@514 837
jdaggett@890 838 <h5 class="no-num no-toc"> <span class=index-def id=sans-serif0
jdaggett@890 839 title="sans-serif, definition of"> <a name=sans-serif-def><dfn
jdaggett@890 840 id=sans-serif>sans-serif</dfn></a></span></h5>
jdaggett@514 841
jdaggett@8178 842 <p>Glyphs in sans-serif fonts, as the term is used in CSS, are generally
jdaggett@8178 843 low contrast (vertical and horizontal stems have the close to the same
jdaggett@8178 844 thickness) and have stroke endings that are plain -- without any flaring,
jdaggett@8178 845 cross stroke, or other ornamentation. Sans-serif fonts are typically
jdaggett@8178 846 proportionately-spaced. They often have little variation between thick and
jdaggett@8178 847 thin strokes, compared to fonts from the ‘<a href="#serif"><code
jdaggett@4624 848 class=property>serif</code></a>’ family. CSS uses the term ‘<a
jdaggett@4624 849 href="#sans-serif"><code class=property>sans-serif</code></a>’ to apply
jdaggett@4624 850 to a font for any script, although other names may be more familiar for
jdaggett@3041 851 particular scripts, such as Gothic (Japanese), Hei (Chinese), or Gulim
jdaggett@1148 852 (Korean). Any font that is so described may be used to represent the
jdaggett@4624 853 generic ‘<a href="#sans-serif"><code
jdaggett@4624 854 class=property>sans-serif</code></a>’ family.
jdaggett@518 855
jdaggett@1150 856 <div class=figure><img alt="sample sans-serif fonts"
jdaggett@1150 857 src=sansserifexamples.png>
jdaggett@890 858 <p class=caption>Sample sans-serif fonts
jdaggett@514 859 </div>
jdaggett@514 860
jdaggett@890 861 <h5 class="no-num no-toc"> <span class=index-def id=cursive0
jdaggett@545 862 title="cursive, definition of"> <a name=cursive-def><dfn
jdaggett@890 863 id=cursive>cursive</dfn></a></span></h5>
jdaggett@545 864
jdaggett@8178 865 <p>Glyphs in cursive fonts generally use a more informal script style, and
jdaggett@8178 866 the result looks more like handwritten pen or brush writing than printed
jdaggett@8178 867 letterwork. CSS uses the term ‘<a href="#cursive"><code
jdaggett@8178 868 class=property>cursive</code></a>’ to apply to a font for any script,
jdaggett@8178 869 although other names such as Chancery, Brush, Swing and Script are also
jdaggett@8178 870 used in font names.
jdaggett@514 871
jdaggett@1150 872 <div class=figure><img alt="sample cursive fonts" src=cursiveexamples.png>
jdaggett@890 873 <p class=caption>Sample cursive fonts
jdaggett@514 874 </div>
jdaggett@514 875
jdaggett@890 876 <h5 class="no-num no-toc"> <span class=index-def id=fantasy0
jdaggett@545 877 title="fantasy, definition of"> <a name=fantasy-def><dfn
jdaggett@890 878 id=fantasy>fantasy</dfn></a></span></h5>
jdaggett@514 879
jdaggett@8178 880 <p>Fantasy fonts are primarily decorative or expressive fonts that contain
jdaggett@8178 881 playful representations of characters. These do not include Pi or Picture
jdaggett@8178 882 fonts which do not represent actual characters.
jdaggett@514 883
jdaggett@1150 884 <div class=figure><img alt="sample fantasy fonts" src=fantasyexamples.png>
jdaggett@890 885 <p class=caption>Sample fantasy fonts
jdaggett@514 886 </div>
jdaggett@514 887
jdaggett@890 888 <h5 class="no-num no-toc"> <span class=index-def id=monospace0
jdaggett@545 889 title="monospace, definition of"> <a name=monospace-def><dfn
jdaggett@890 890 id=monospace>monospace</dfn></a></span></h5>
jdaggett@514 891
jdaggett@514 892 <p>The sole criterion of a monospace font is that all glyphs have the same
jdaggett@518 893 fixed width. This is often used to render samples of computer code.
jdaggett@514 894
jdaggett@1150 895 <div class=figure><img alt="sample monospace fonts"
jdaggett@1150 896 src=monospaceexamples.png>
jdaggett@890 897 <p class=caption>Sample monospace fonts
jdaggett@514 898 </div>
jdaggett@512 899 <!-- prop: font-weight -->
jdaggett@512 900
jdaggett@1662 901 <h3 id=font-weight-prop><span class=secno>3.2 </span>Font weight: the <a
jdaggett@1662 902 href="#propdef-font-weight">font-weight</a> property</h3>
jdaggett@1662 903
jdaggett@4624 904 <table class=propdef id=namefont-weightvaluenormal-bold-bolder-l>
jdaggett@484 905 <tbody>
jdaggett@484 906 <tr>
jdaggett@484 907 <td>Name:
jdaggett@484 908
jdaggett@8278 909 <td><dfn id=propdef-font-weight
jdaggett@8278 910 title="font-weight!!property">font-weight</dfn>
jdaggett@484 911
jdaggett@484 912 <tr>
jdaggett@484 913 <td>Value:
jdaggett@484 914
jdaggett@8278 915 <td><a href="#font-weight-normal-value"
jdaggett@8278 916 title="normal!!font-weight">normal</a> | <a href="#bold">bold</a> | <a
jdaggett@8278 917 href="#bolder">bolder</a> | <a href="#lighter">lighter</a> | <a
jdaggett@8278 918 href="#font-weight-numeric-values" title="100...900 weight
jdaggett@8278 919 values">100</a> | <a href="#font-weight-numeric-values"
jdaggett@8278 920 title="100...900 weight values">200</a> | <a
jdaggett@8278 921 href="#font-weight-numeric-values" title="100...900 weight
jdaggett@8278 922 values">300</a> | <a href="#font-weight-numeric-values"
jdaggett@8278 923 title="100...900 weight values">400</a> | <a
jdaggett@8278 924 href="#font-weight-numeric-values" title="100...900 weight
jdaggett@8278 925 values">500</a> | <a href="#font-weight-numeric-values"
jdaggett@8278 926 title="100...900 weight values">600</a> | <a
jdaggett@8278 927 href="#font-weight-numeric-values" title="100...900 weight
jdaggett@8278 928 values">700</a> | <a href="#font-weight-numeric-values"
jdaggett@8278 929 title="100...900 weight values">800</a> | <a
jdaggett@8278 930 href="#font-weight-numeric-values" title="100...900 weight
jdaggett@8278 931 values">900</a>
jdaggett@484 932
jdaggett@484 933 <tr>
jdaggett@484 934 <td>Initial:
jdaggett@484 935
jdaggett@484 936 <td>normal
jdaggett@484 937
jdaggett@484 938 <tr>
jdaggett@484 939 <td>Applies to:
jdaggett@484 940
jdaggett@484 941 <td>all elements
jdaggett@484 942
jdaggett@484 943 <tr>
jdaggett@484 944 <td>Inherited:
jdaggett@484 945
jdaggett@484 946 <td>yes
jdaggett@484 947
jdaggett@484 948 <tr>
jdaggett@484 949 <td>Percentages:
jdaggett@484 950
jdaggett@484 951 <td>N/A
jdaggett@484 952
jdaggett@484 953 <tr>
jdaggett@484 954 <td>Media:
jdaggett@484 955
jdaggett@484 956 <td>visual
jdaggett@484 957
jdaggett@484 958 <tr>
jdaggett@1148 959 <td>Computed value:
jdaggett@484 960
jdaggett@8177 961 <td>numeric weight value (see description)
jdaggett@7377 962
jdaggett@7377 963 <tr>
jdaggett@7377 964 <td>Animatable:
jdaggett@7377 965
jdaggett@7377 966 <td>as <a
jdaggett@7377 967 href="http://dev.w3.org/csswg/css3-transitions/#animtype-font-weight">font
jdaggett@7377 968 weight</a>
jdaggett@484 969 </table>
jdaggett@484 970
jdaggett@8278 971 <p>The <a href="#propdef-font-weight"
jdaggett@8278 972 title="font-weight!!property">‘<code
jdaggett@8278 973 class=property>font-weight</code>’</a> property specifies the weight of
jdaggett@8278 974 glyphs in the font, their degree of blackness or stroke thickness.
jdaggett@531 975
jdaggett@531 976 <p>Values have the following meanings:
jdaggett@512 977
jdaggett@512 978 <dl>
jdaggett@8278 979 <dt><dfn id=font-weight-numeric-values title="100...900 weight values">100
jdaggett@8278 980 to 900</dfn>
jdaggett@512 981
jdaggett@512 982 <dd>These values form an ordered sequence, where each number indicates a
jdaggett@514 983 weight that is at least as dark as its predecessor. These roughly
jdaggett@514 984 correspond to the commonly used weight names below:
jdaggett@512 985 </dl>
jdaggett@512 986
jdaggett@512 987 <ul>
jdaggett@512 988 <li>100 - Thin
jdaggett@512 989
jdaggett@518 990 <li>200 - Extra Light (Ultra Light)
jdaggett@512 991
jdaggett@512 992 <li>300 - Light
jdaggett@512 993
jdaggett@512 994 <li>400 - Normal
jdaggett@512 995
jdaggett@512 996 <li>500 - Medium
jdaggett@512 997
jdaggett@518 998 <li>600 - Semi Bold (Demi Bold)
jdaggett@512 999
jdaggett@512 1000 <li>700 - Bold
jdaggett@512 1001
jdaggett@518 1002 <li>800 - Extra Bold (Ultra Bold)
jdaggett@512 1003
jdaggett@512 1004 <li>900 - Black (Heavy)
jdaggett@512 1005 </ul>
jdaggett@512 1006
jdaggett@512 1007 <dl>
jdaggett@8278 1008 <dt><dfn id=font-weight-normal-value
jdaggett@8278 1009 title="normal!!font-weight">normal</dfn>
jdaggett@512 1010
jdaggett@1148 1011 <dd>Same as ‘<code class=css>400</code>’.
jdaggett@512 1012
jdaggett@8278 1013 <dt><dfn id=bold>bold</dfn>
jdaggett@512 1014
jdaggett@1148 1015 <dd>Same as ‘<code class=css>700</code>’.
jdaggett@512 1016
jdaggett@8278 1017 <dt><dfn id=bolder>bolder</dfn>
jdaggett@512 1018
jdaggett@8177 1019 <dd>Specifies a bolder weight than the inherited value.
jdaggett@512 1020
jdaggett@8278 1021 <dt><dfn id=lighter>lighter</dfn>
jdaggett@512 1022
jdaggett@8177 1023 <dd>Specifies a lighter weight than the inherited value.
jdaggett@512 1024 </dl>
jdaggett@512 1025
jdaggett@8177 1026 <p>Font formats that use a scale other than a nine-step scale should map
jdaggett@531 1027 their scale onto the CSS scale so that 400 roughly corresponds with a face
jdaggett@531 1028 that would be labeled as Regular, Book, Roman and 700 roughly matches a
jdaggett@531 1029 face that would be labeled as Bold. Or weights may be inferred from the
jdaggett@531 1030 style names, ones that correspond roughly with the scale above. The scale
jdaggett@1662 1031 is relative, so a face with a larger weight value must never appear
jdaggett@1148 1032 lighter. If style names are used to infer weights, care should be taken to
jdaggett@1148 1033 handle variations in style names across locales.
jdaggett@531 1034
jdaggett@531 1035 <p>Quite often there are only a few weights available for a particular font
jdaggett@534 1036 family. When a weight is specified for which no face exists, a face with a
jdaggett@534 1037 nearby weight is used. In general, bold weights map to faces with heavier
jdaggett@1269 1038 weights and light weights map to faces with lighter weights (see the <a
jdaggett@1269 1039 href="#font-matching-algorithm">font matching section below</a> for a
jdaggett@1269 1040 precise definition). The examples here illustrate which face is used for
jdaggett@1269 1041 different weights, grey indicates a face for that weight does not exist so
jdaggett@1269 1042 a face with a nearby weight is used:
jdaggett@532 1043
jdaggett@1150 1044 <div class=figure><img alt="weight mappings for a family with 400, 700 and
jdaggett@1150 1045 900 weights" src=optimaweights.png>
jdaggett@532 1046 <p class=caption>Weight mappings for a font family with 400, 700 and 900
jdaggett@890 1047 weight faces
jdaggett@518 1048 </div>
jdaggett@518 1049
jdaggett@1150 1050 <div class=figure><img alt="weight mappings for a family with 300, 600
jdaggett@1150 1051 weights" src=hiraginoweights.png>
jdaggett@532 1052 <p class=caption>Weight mappings for a font family with 300 and 600 weight
jdaggett@890 1053 faces
jdaggett@531 1054 </div>
jdaggett@518 1055
jdaggett@2487 1056 <p>Although the practice is not well-loved by typographers, bold faces are
jdaggett@2487 1057 often synthesized by user agents for faces that lack actual bold faces.
jdaggett@2487 1058 For the purposes of style matching, these faces must be treated as if they
jdaggett@8177 1059 exist within the family. Authors can explicitly avoid this behavior by
jdaggett@8177 1060 using the ‘<a href="#propdef-font-synthesis"><code
jdaggett@8177 1061 class=property>font-synthesis</code></a>’ property.
jdaggett@8177 1062
jdaggett@8278 1063 <p>Specified values of ‘<a href="#bolder"><code
jdaggett@8278 1064 class=property>bolder</code></a>’ and ‘<a href="#lighter"><code
jdaggett@8278 1065 class=property>lighter</code></a>’ indicate weights relative to the
jdaggett@8177 1066 weight of the parent element. The computed weight is calculated based on
jdaggett@8278 1067 the inherited <a href="#propdef-font-weight"
jdaggett@8278 1068 title="font-weight!!property">‘<code
jdaggett@8278 1069 class=property>font-weight</code>’</a> value using the chart below.
jdaggett@1148 1070
jdaggett@6651 1071 <table class=data id=bolderlighter summary="Bolder/lighter mappings">
jdaggett@1148 1072 <thead>
jdaggett@1148 1073 <tr>
jdaggett@6651 1074 <th>Inherited value
jdaggett@6651 1075
jdaggett@6651 1076 <th>bolder
jdaggett@6651 1077
jdaggett@6651 1078 <th>lighter
jdaggett@1148 1079
jdaggett@1148 1080 <tbody>
jdaggett@1148 1081 <tr>
jdaggett@1244 1082 <th>100
jdaggett@1148 1083
jdaggett@1148 1084 <td>400
jdaggett@1148 1085
jdaggett@1148 1086 <td>100
jdaggett@1148 1087
jdaggett@1148 1088 <tr>
jdaggett@1244 1089 <th>200
jdaggett@1148 1090
jdaggett@1148 1091 <td>400
jdaggett@1148 1092
jdaggett@1148 1093 <td>100
jdaggett@1148 1094
jdaggett@1148 1095 <tr>
jdaggett@1244 1096 <th>300
jdaggett@1148 1097
jdaggett@1148 1098 <td>400
jdaggett@1148 1099
jdaggett@1148 1100 <td>100
jdaggett@1148 1101
jdaggett@1148 1102 <tr>
jdaggett@1244 1103 <th>400
jdaggett@1148 1104
jdaggett@1148 1105 <td>700
jdaggett@1148 1106
jdaggett@1148 1107 <td>100
jdaggett@1148 1108
jdaggett@1148 1109 <tr>
jdaggett@1244 1110 <th>500
jdaggett@1148 1111
jdaggett@1148 1112 <td>700
jdaggett@1148 1113
jdaggett@1148 1114 <td>100
jdaggett@1148 1115
jdaggett@1148 1116 <tr>
jdaggett@1244 1117 <th>600
jdaggett@1148 1118
jdaggett@1148 1119 <td>900
jdaggett@1148 1120
jdaggett@1148 1121 <td>400
jdaggett@1148 1122
jdaggett@1148 1123 <tr>
jdaggett@1244 1124 <th>700
jdaggett@1148 1125
jdaggett@1148 1126 <td>900
jdaggett@1148 1127
jdaggett@1148 1128 <td>400
jdaggett@1148 1129
jdaggett@1148 1130 <tr>
jdaggett@1244 1131 <th>800
jdaggett@1148 1132
jdaggett@1148 1133 <td>900
jdaggett@1148 1134
jdaggett@1148 1135 <td>700
jdaggett@1148 1136
jdaggett@1148 1137 <tr>
jdaggett@1244 1138 <th>900
jdaggett@1148 1139
jdaggett@1148 1140 <td>900
jdaggett@1148 1141
jdaggett@1148 1142 <td>700
jdaggett@1148 1143 </table>
jdaggett@1148 1144
jdaggett@1148 1145 <p>The table above is equivalent to selecting the next relative bolder or
jdaggett@1148 1146 lighter face, given a font family containing normal and bold faces along
jdaggett@1148 1147 with a thin and a heavy face. Authors who desire finer control over the
jdaggett@8177 1148 exact weight values used for a given element may use numerical values
jdaggett@1148 1149 instead of relative weights.</p>
jdaggett@512 1150 <!-- prop: font-stretch -->
jdaggett@512 1151
jdaggett@1662 1152 <h3 id=font-stretch-prop><span class=secno>3.3 </span>Font width: the <a
jdaggett@1662 1153 href="#propdef-font-stretch">font-stretch</a> property</h3>
jdaggett@1662 1154
jdaggett@8278 1155 <table class=propdef id=namefont-stretchvalue-normal-ultra-conde>
jdaggett@484 1156 <tbody>
jdaggett@484 1157 <tr>
jdaggett@484 1158 <td>Name:
jdaggett@484 1159
jdaggett@8278 1160 <td><dfn id=propdef-font-stretch
jdaggett@8278 1161 title="font-stretch!!property">font-stretch</dfn>
jdaggett@484 1162
jdaggett@484 1163 <tr>
jdaggett@484 1164 <td>Value:
jdaggett@484 1165
jdaggett@8278 1166 <td> <a href="#font-stretch-normal-value"
jdaggett@8278 1167 title="normal!!font-stretch">normal</a> | <a
jdaggett@8278 1168 href="#ultra-condensed">ultra-condensed</a> | <a
jdaggett@8278 1169 href="#extra-condensed">extra-condensed</a> | <a
jdaggett@8278 1170 href="#condensed">condensed</a> | <a
jdaggett@8278 1171 href="#semi-condensed-">semi-condensed</a> | <a
jdaggett@8278 1172 href="#semi-expanded">semi-expanded</a> | <a
jdaggett@8278 1173 href="#expanded">expanded</a> | <a
jdaggett@8278 1174 href="#extra-expanded">extra-expanded</a> | <a
jdaggett@8278 1175 href="#ultra-expanded">ultra-expanded</a>
jdaggett@484 1176
jdaggett@484 1177 <tr>
jdaggett@484 1178 <td>Initial:
jdaggett@484 1179
jdaggett@484 1180 <td>normal
jdaggett@484 1181
jdaggett@484 1182 <tr>
jdaggett@484 1183 <td>Applies to:
jdaggett@484 1184
jdaggett@484 1185 <td>all elements
jdaggett@484 1186
jdaggett@484 1187 <tr>
jdaggett@484 1188 <td>Inherited:
jdaggett@484 1189
jdaggett@484 1190 <td>yes
jdaggett@484 1191
jdaggett@484 1192 <tr>
jdaggett@484 1193 <td>Percentages:
jdaggett@484 1194
jdaggett@484 1195 <td>N/A
jdaggett@484 1196
jdaggett@484 1197 <tr>
jdaggett@484 1198 <td>Media:
jdaggett@484 1199
jdaggett@484 1200 <td>visual
jdaggett@484 1201
jdaggett@484 1202 <tr>
jdaggett@1148 1203 <td>Computed value:
jdaggett@484 1204
jdaggett@484 1205 <td>as specified
jdaggett@7377 1206
jdaggett@7377 1207 <tr>
jdaggett@7377 1208 <td>Animatable:
jdaggett@7377 1209
jdaggett@7377 1210 <td>as <a href="#font-stretch-animation">font stretch</a>
jdaggett@484 1211 </table>
jdaggett@484 1212
jdaggett@8278 1213 <p>The <a href="#propdef-font-stretch"
jdaggett@8278 1214 title="font-stretch!!property">‘<code
jdaggett@8278 1215 class=property>font-stretch</code>’</a> property selects a normal,
jdaggett@8278 1216 condensed, or expanded face from a font family. Absolute keyword values
jdaggett@8278 1217 have the following ordering, from narrowest to widest:
jdaggett@512 1218
jdaggett@512 1219 <ul>
jdaggett@8278 1220 <li><dfn id=ultra-condensed>ultra-condensed</dfn>
jdaggett@8278 1221
jdaggett@8278 1222 <li><dfn id=extra-condensed>extra-condensed</dfn>
jdaggett@8278 1223
jdaggett@8278 1224 <li><dfn id=condensed>condensed</dfn>
jdaggett@8278 1225
jdaggett@8278 1226 <li><dfn id=semi-condensed->semi-condensed </dfn>
jdaggett@8278 1227
jdaggett@8278 1228 <li><dfn id=font-stretch-normal-value
jdaggett@8278 1229 title="normal!!font-stretch">normal</dfn>
jdaggett@8278 1230
jdaggett@8278 1231 <li><dfn id=semi-expanded>semi-expanded</dfn>
jdaggett@8278 1232
jdaggett@8278 1233 <li><dfn id=expanded>expanded</dfn>
jdaggett@8278 1234
jdaggett@8278 1235 <li><dfn id=extra-expanded>extra-expanded</dfn>
jdaggett@8278 1236
jdaggett@8278 1237 <li><dfn id=ultra-expanded>ultra-expanded</dfn>
jdaggett@512 1238 </ul>
jdaggett@512 1239
jdaggett@8197 1240 <p>When a face does not exist for a given width, normal or condensed values
jdaggett@8197 1241 map to a narrower face, otherwise a wider face. Conversely, expanded
jdaggett@8197 1242 values map to a wider face, otherwise a narrower face. The figure below
jdaggett@8197 1243 shows how the nine font-stretch property settings affect font selection
jdaggett@8197 1244 for font family containing a variety of widths, grey indicates a width for
jdaggett@8197 1245 which no face exists and a different width is substituted:
jdaggett@1148 1246
jdaggett@1150 1247 <div class=figure><img alt="width mappings for a family with condensed,
jdaggett@1150 1248 normal and expanded faces" src=universwidths.png>
jdaggett@1148 1249 <p class=caption>Width mappings for a font family with condensed, normal
jdaggett@1148 1250 and expanded width faces
jdaggett@1148 1251 </div>
jdaggett@7377 1252
jdaggett@7377 1253 <p id=font-stretch-animation>Animation of font stretch: Font stretch is
jdaggett@7377 1254 interpolated in discrete steps. The interpolation happens as though the
jdaggett@7377 1255 ordered values are equally spaced real numbers. The interpolation result
jdaggett@7377 1256 is rounded to the nearest value, with values exactly halfway between two
jdaggett@7377 1257 values rounded towards the later value in the list above.</p>
jdaggett@512 1258 <!-- prop: font-style -->
jdaggett@512 1259
jdaggett@1662 1260 <h3 id=font-style-prop><span class=secno>3.4 </span>Font style: the <a
jdaggett@1662 1261 href="#propdef-font-style">font-style</a> property</h3>
jdaggett@1662 1262
jdaggett@4624 1263 <table class=propdef id=namefont-stylevaluenormal-italic-oblique>
jdaggett@484 1264 <tbody>
jdaggett@484 1265 <tr>
jdaggett@484 1266 <td>Name:
jdaggett@484 1267
jdaggett@8278 1268 <td><dfn id=propdef-font-style
jdaggett@8278 1269 title="font-style!!property">font-style</dfn>
jdaggett@484 1270
jdaggett@484 1271 <tr>
jdaggett@484 1272 <td>Value:
jdaggett@484 1273
jdaggett@8278 1274 <td><a href="#font-style-normal-value"
jdaggett@8278 1275 title="normal!!font-style">normal</a> | <a href="#italic">italic</a> |
jdaggett@8278 1276 <a href="#oblique">oblique</a>
jdaggett@484 1277
jdaggett@484 1278 <tr>
jdaggett@484 1279 <td>Initial:
jdaggett@484 1280
jdaggett@484 1281 <td>normal
jdaggett@484 1282
jdaggett@484 1283 <tr>
jdaggett@484 1284 <td>Applies to:
jdaggett@484 1285
jdaggett@484 1286 <td>all elements
jdaggett@484 1287
jdaggett@484 1288 <tr>
jdaggett@484 1289 <td>Inherited:
jdaggett@484 1290
jdaggett@484 1291 <td>yes
jdaggett@484 1292
jdaggett@484 1293 <tr>
jdaggett@484 1294 <td>Percentages:
jdaggett@484 1295
jdaggett@484 1296 <td>N/A
jdaggett@484 1297
jdaggett@484 1298 <tr>
jdaggett@484 1299 <td>Media:
jdaggett@484 1300
jdaggett@484 1301 <td>visual
jdaggett@484 1302
jdaggett@484 1303 <tr>
jdaggett@1148 1304 <td>Computed value:
jdaggett@484 1305
jdaggett@484 1306 <td>as specified
jdaggett@7377 1307
jdaggett@7377 1308 <tr>
jdaggett@7377 1309 <td>Animatable:
jdaggett@7377 1310
jdaggett@7377 1311 <td>no
jdaggett@484 1312 </table>
jdaggett@484 1313
jdaggett@8278 1314 <p>The <a href="#propdef-font-style" title="font-style!!property">‘<code
jdaggett@8278 1315 class=property>font-style</code>’</a> property allows italic or oblique
jdaggett@8278 1316 faces to be selected. Italic forms are generally cursive in nature while
jdaggett@8278 1317 oblique faces are typically sloped versions of the regular face. Oblique
jdaggett@8278 1318 faces can be simulated by artificially sloping the glyphs of the regular
jdaggett@8278 1319 face. Compare the artificially sloped renderings of Palatino ‘<code
jdaggett@2556 1320 class=property>a</code>’ and Baskerville ‘<code
jdaggett@1148 1321 class=property>N</code>’ in grey with the actual italic versions:
jdaggett@518 1322
jdaggett@1150 1323 <div class=figure><img alt="artificial sloping vs. real italics"
jdaggett@1150 1324 src=realvsfakeitalics.png>
jdaggett@890 1325 <p class=caption>Artificial sloping versus real italics
jdaggett@512 1326 </div>
jdaggett@518 1327
jdaggett@8278 1328 <p>Values have the following meanings:
jdaggett@8278 1329
jdaggett@8278 1330 <dl>
jdaggett@8278 1331 <dt><dfn id=font-style-normal-value
jdaggett@8278 1332 title="normal!!font-style">normal</dfn>
jdaggett@8278 1333
jdaggett@8278 1334 <dd>selects a face that is classified as a normal face, one that is
jdaggett@8278 1335 neither italic or obliqued
jdaggett@8278 1336
jdaggett@8278 1337 <dt><dfn id=italic>italic</dfn>
jdaggett@8278 1338
jdaggett@8278 1339 <dd>selects a font that is labeled as an italic face, or an oblique face
jdaggett@8278 1340 if one is not
jdaggett@8278 1341
jdaggett@8278 1342 <dt><dfn id=oblique>oblique</dfn>
jdaggett@8278 1343
jdaggett@8278 1344 <dd>selects a font that is labeled as an oblique face, or an italic face
jdaggett@8278 1345 if one is not
jdaggett@8278 1346 </dl>
jdaggett@8278 1347
jdaggett@8278 1348 <p>If no italic or oblique face is available, oblique faces can be
jdaggett@8363 1349 synthesized by rendering non-obliqued faces with an artificial obliquing
jdaggett@8363 1350 operation. The use of these artificially obliqued faces can be disabled
jdaggett@8363 1351 using the ‘<a href="#propdef-font-synthesis"><code
jdaggett@8363 1352 class=property>font-synthesis</code></a>’ property. The details of the
jdaggett@8363 1353 obliquing operation are not explicitly defined.</p>
jdaggett@8363 1354 <!-- resolution on the "undefined" nature of synthetics: http://www.w3.org/2013/06/06-css-minutes.html#item03 -->
jdaggett@518 1355
jdaggett@518 1356 <p>Many scripts lack the tradition of mixing a cursive form within text
jdaggett@518 1357 rendered with a normal face. Chinese, Japanese and Korean fonts almost
jdaggett@518 1358 always lack italic or oblique faces. Fonts that support a mixture of
jdaggett@518 1359 scripts will sometimes omit specific scripts such as Arabic from the set
jdaggett@518 1360 of glyphs supported in the italic face. User agents should be careful
jdaggett@8225 1361 about making <a href="#character-map"><em>character map</em></a>
jdaggett@8363 1362 assumptions across faces when implementing support for <a
jdaggett@8363 1363 href="#system-font-fallback"><em>system font fallback</em></a>.</p>
jdaggett@1662 1364 <!-- prop: font-size -->
jdaggett@1662 1365
jdaggett@1662 1366 <h3 id=font-size-prop><span class=secno>3.5 </span>Font size: the <a
jdaggett@1662 1367 href="#propdef-font-size">font-size</a> property</h3>
jdaggett@1662 1368
jdaggett@8225 1369 <table class=propdef id=namefont-sizevalueltabsolute-sizegt-ltre>
jdaggett@484 1370 <tbody>
jdaggett@484 1371 <tr>
jdaggett@484 1372 <td>Name:
jdaggett@484 1373
jdaggett@1662 1374 <td><dfn id=propdef-font-size>font-size</dfn>
jdaggett@484 1375
jdaggett@484 1376 <tr>
jdaggett@484 1377 <td>Value:
jdaggett@484 1378
jdaggett@8225 1379 <td><a href="#absolute-size-value"><var>&lt;absolute-size&gt;</var></a>
jdaggett@8225 1380 | <a href="#relative-size-value"><var>&lt;relative-size&gt;</var></a> |
jdaggett@8225 1381 <a href="#length-size-value"><var>&lt;length&gt;</var></a> | <a
jdaggett@8225 1382 href="#percentage-size-value"><var>&lt;percentage&gt;</var></a>
jdaggett@484 1383
jdaggett@484 1384 <tr>
jdaggett@484 1385 <td>Initial:
jdaggett@484 1386
jdaggett@484 1387 <td>medium
jdaggett@484 1388
jdaggett@484 1389 <tr>
jdaggett@484 1390 <td>Applies to:
jdaggett@484 1391
jdaggett@484 1392 <td>all elements
jdaggett@484 1393
jdaggett@484 1394 <tr>
jdaggett@484 1395 <td>Inherited:
jdaggett@484 1396
jdaggett@484 1397 <td>yes
jdaggett@484 1398
jdaggett@484 1399 <tr>
jdaggett@484 1400 <td>Percentages:
jdaggett@484 1401
jdaggett@484 1402 <td>refer to parent element's font size
jdaggett@484 1403
jdaggett@484 1404 <tr>
jdaggett@484 1405 <td>Media:
jdaggett@484 1406
jdaggett@484 1407 <td>visual
jdaggett@484 1408
jdaggett@484 1409 <tr>
jdaggett@1148 1410 <td>Computed value:
jdaggett@484 1411
jdaggett@484 1412 <td>absolute length
jdaggett@7377 1413
jdaggett@7377 1414 <tr>
jdaggett@7377 1415 <td>Animatable:
jdaggett@7377 1416
jdaggett@7377 1417 <td>as <a
jdaggett@7377 1418 href="http://dev.w3.org/csswg/css3-transitions/#animtype-length">length</a>
jdaggett@484 1419 </table>
jdaggett@484 1420
jdaggett@512 1421 <p>This property indicates the desired height of glyphs from the font. For
jdaggett@512 1422 scalable fonts, the font-size is a scale factor applied to the EM unit of
jdaggett@512 1423 the font. (Note that certain glyphs may bleed outside their EM box.) For
jdaggett@512 1424 non-scalable fonts, the font-size is converted into absolute units and
jdaggett@512 1425 matched against the declared font-size of the font, using the same
jdaggett@512 1426 absolute coordinate space for both of the matched values. Values have the
jdaggett@512 1427 following meanings:
jdaggett@512 1428
jdaggett@512 1429 <dl>
jdaggett@8225 1430 <dt><dfn id=absolute-size-value><var>&lt;absolute-size&gt;</var></dfn>
jdaggett@8225 1431
jdaggett@8225 1432 <dd> An <a
jdaggett@8225 1433 href="#absolute-size-value"><var>&lt;absolute-size&gt;</var></a> keyword
jdaggett@8225 1434 refers to an entry in a table of font sizes computed and kept by the user
jdaggett@8225 1435 agent. Possible values are:
jdaggett@512 1436 <p> [ xx-small | x-small | small | medium | large | x-large | xx-large ]</p>
jdaggett@512 1437
jdaggett@8225 1438 <dt><dfn id=relative-size-value><var>&lt;relative-size&gt;</var></dfn>
jdaggett@8225 1439
jdaggett@8225 1440 <dd> A <a href="#relative-size-value"><var>&lt;relative-size&gt;</var></a>
jdaggett@8225 1441 keyword is interpreted relative to the table of font sizes and the
jdaggett@8225 1442 computed ‘<a href="#propdef-font-size"><code
jdaggett@8225 1443 class=property>font-size</code></a>’ of the parent element. Possible
jdaggett@8225 1444 values are:
jdaggett@890 1445 <p> [ larger | smaller ]
jdaggett@890 1446
jdaggett@1148 1447 <p> For example, if the parent element has a font size of ‘<code
jdaggett@1148 1448 class=property>medium</code>’, a value of ‘<code
jdaggett@1148 1449 class=property>larger</code>’ will make the font size of the current
jdaggett@1148 1450 element be ‘<code class=property>large</code>’. If the parent
jdaggett@1148 1451 element's size is not close to a table entry, the user agent is free to
jdaggett@1148 1452 interpolate between table entries or round off to the closest one. The
jdaggett@1148 1453 user agent may have to extrapolate table values if the numerical value
jdaggett@1148 1454 goes beyond the keywords.
jdaggett@512 1455
jdaggett@8225 1456 <dt><dfn id=length-size-value><var>&lt;length&gt;</var></dfn>
jdaggett@512 1457
jdaggett@8187 1458 <dd>A length value specifies an absolute font size (independent of the
jdaggett@8187 1459 user agent's font table). Negative lengths are illegal.
jdaggett@512 1460
jdaggett@8225 1461 <dt><dfn id=percentage-size-value><var>&lt;percentage&gt;</var></dfn>
jdaggett@512 1462
jdaggett@512 1463 <dd>A percentage value specifies an absolute font size relative to the
jdaggett@512 1464 parent element's font size. Use of percentage values, or values in
jdaggett@1148 1465 ‘<code class=property>em</code>’s, leads to more robust and
jdaggett@512 1466 cascadable style sheets.
jdaggett@512 1467 </dl>
jdaggett@512 1468
jdaggett@8187 1469 <p>The following table provides user agent guidelines for the absolute-size
jdaggett@8187 1470 scaling factor and their mapping to HTML heading and absolute font-sizes.
jdaggett@8187 1471 The ‘<code class=property>medium</code>’ value is used as the
jdaggett@8187 1472 reference middle value. The user agent may fine-tune these values for
jdaggett@8187 1473 different fonts or different types of display devices.
jdaggett@1244 1474
jdaggett@1244 1475 <table class=data>
jdaggett@1152 1476 <thead>
jdaggett@1152 1477 <tr>
jdaggett@1152 1478 <th>CSS absolute-size values
jdaggett@1152 1479
jdaggett@1152 1480 <th>xx-small
jdaggett@1152 1481
jdaggett@1152 1482 <th>x-small
jdaggett@1152 1483
jdaggett@1152 1484 <th>small
jdaggett@1152 1485
jdaggett@1152 1486 <th>medium
jdaggett@1152 1487
jdaggett@1152 1488 <th>large
jdaggett@1152 1489
jdaggett@1152 1490 <th>x-large
jdaggett@1152 1491
jdaggett@1152 1492 <th>xx-large
jdaggett@1152 1493
jdaggett@1152 1494 <th> 
jdaggett@1152 1495
jdaggett@512 1496 <tbody>
jdaggett@512 1497 <tr>
jdaggett@1152 1498 <th>scaling factor
jdaggett@1152 1499
jdaggett@1152 1500 <td>3/5
jdaggett@1152 1501
jdaggett@1152 1502 <td>3/4
jdaggett@1152 1503
jdaggett@1152 1504 <td>8/9
jdaggett@1152 1505
jdaggett@1152 1506 <td>1
jdaggett@1152 1507
jdaggett@1152 1508 <td>6/5
jdaggett@1152 1509
jdaggett@1152 1510 <td>3/2
jdaggett@1152 1511
jdaggett@1152 1512 <td>2/1
jdaggett@1152 1513
jdaggett@1152 1514 <td>3/1
jdaggett@512 1515
jdaggett@512 1516 <tr>
jdaggett@8187 1517 <th>HTML headings
jdaggett@1152 1518
jdaggett@1152 1519 <td>h6
jdaggett@1152 1520
jdaggett@1152 1521 <td> 
jdaggett@1152 1522
jdaggett@1152 1523 <td>h5
jdaggett@1152 1524
jdaggett@1152 1525 <td>h4
jdaggett@1152 1526
jdaggett@1152 1527 <td>h3
jdaggett@1152 1528
jdaggett@1152 1529 <td>h2
jdaggett@1152 1530
jdaggett@1152 1531 <td>h1
jdaggett@1152 1532
jdaggett@1152 1533 <td> 
jdaggett@512 1534
jdaggett@512 1535 <tr>
jdaggett@8187 1536 <th>HTML font sizes
jdaggett@1152 1537
jdaggett@1152 1538 <td>1
jdaggett@1152 1539
jdaggett@1152 1540 <td> 
jdaggett@1152 1541
jdaggett@1152 1542 <td>2
jdaggett@1152 1543
jdaggett@1152 1544 <td>3
jdaggett@1152 1545
jdaggett@1152 1546 <td>4
jdaggett@1152 1547
jdaggett@1152 1548 <td>5
jdaggett@1152 1549
jdaggett@1152 1550 <td>6
jdaggett@1152 1551
jdaggett@1152 1552 <td>7
jdaggett@512 1553 </table>
jdaggett@512 1554
jdaggett@512 1555 <p class=note><em><strong>Note 1.</strong> To preserve readability, an UA
jdaggett@512 1556 applying these guidelines should nevertheless avoid creating font-size
jdaggett@8272 1557 resulting in less than 9 device pixels per EM unit on a computer
jdaggett@8272 1558 display.</em>
jdaggett@512 1559
jdaggett@512 1560 <p class=note><em><strong>Note 2.</strong> In CSS1, the suggested scaling
jdaggett@512 1561 factor between adjacent indexes was 1.5 which user experience proved to be
jdaggett@512 1562 too large. In CSS2, the suggested scaling factor for computer screen
jdaggett@512 1563 between adjacent indexes was 1.2 which still created issues for the small
jdaggett@512 1564 sizes. The new scaling factor varies between each index to provide a
jdaggett@512 1565 better readability.</em>
jdaggett@512 1566
jdaggett@6659 1567 <p>The actual value of this property may differ from the computed value due
jdaggett@6659 1568 a numerical value on ‘<a href="#propdef-font-size-adjust"><code
jdaggett@4624 1569 class=property>font-size-adjust</code></a>’ and the unavailability of
jdaggett@4624 1570 certain font sizes.
jdaggett@512 1571
jdaggett@512 1572 <p>Child elements inherit the computed <a class=noxref
jdaggett@6659 1573 href="#font-size-prop"> <span class=property>‘<code
jdaggett@1148 1574 class=property>font-size</code>’</span></a> value (otherwise, the effect
jdaggett@2556 1575 of <a class=noxref href="#font-size-adjust-prop"><span
jdaggett@2556 1576 class=property>‘<code
jdaggett@1148 1577 class=property>font-size-adjust</code>’</span></a> would compound).
jdaggett@512 1578
jdaggett@512 1579 <div class=example>
jdaggett@8699 1580 <p style="display:none">Example(s):</p>
jdaggett@890 1581
jdaggett@512 1582 <pre>p { font-size: 12pt; }
jdaggett@512 1583 blockquote { font-size: larger }
jdaggett@512 1584 em { font-size: 150% }
jdaggett@512 1585 em { font-size: 1.5em }
jdaggett@512 1586 </pre>
jdaggett@512 1587 </div>
jdaggett@512 1588 <!-- prop: font-size-adjust -->
jdaggett@512 1589
jdaggett@1662 1590 <h3 id=font-size-adjust-prop><span class=secno>3.6 </span>Relative sizing:
jdaggett@1662 1591 the <a href="#propdef-font-size-adjust">font-size-adjust</a> property</h3>
jdaggett@1662 1592
jdaggett@6659 1593 <table class=propdef id=namefont-size-adjustvaluenone-auto-ltnum>
jdaggett@484 1594 <tbody>
jdaggett@484 1595 <tr>
jdaggett@484 1596 <td>Name:
jdaggett@484 1597
jdaggett@1662 1598 <td><dfn id=propdef-font-size-adjust>font-size-adjust</dfn>
jdaggett@484 1599
jdaggett@484 1600 <tr>
jdaggett@484 1601 <td>Value:
jdaggett@484 1602
jdaggett@8278 1603 <td><a href="#font-size-adjust-none-value"
jdaggett@8278 1604 title="none!!font-size-adjust">none</a> | <a
jdaggett@8278 1605 href="#font-size-adjust-auto-value"
jdaggett@8278 1606 title="auto!!font-size-adjust">auto</a> | <a
jdaggett@8225 1607 href="#aspect-ratio-value"><var>&lt;number&gt;</var></a>
jdaggett@484 1608
jdaggett@484 1609 <tr>
jdaggett@484 1610 <td>Initial:
jdaggett@484 1611
jdaggett@484 1612 <td>none
jdaggett@484 1613
jdaggett@484 1614 <tr>
jdaggett@484 1615 <td>Applies to:
jdaggett@484 1616
jdaggett@484 1617 <td>all elements
jdaggett@484 1618
jdaggett@484 1619 <tr>
jdaggett@484 1620 <td>Inherited:
jdaggett@484 1621
jdaggett@484 1622 <td>yes
jdaggett@484 1623
jdaggett@484 1624 <tr>
jdaggett@484 1625 <td>Percentages:
jdaggett@484 1626
jdaggett@554 1627 <td>N/A
jdaggett@484 1628
jdaggett@484 1629 <tr>
jdaggett@484 1630 <td>Media:
jdaggett@484 1631
jdaggett@484 1632 <td>visual
jdaggett@484 1633
jdaggett@484 1634 <tr>
jdaggett@1148 1635 <td>Computed value:
jdaggett@484 1636
jdaggett@554 1637 <td>as specified
jdaggett@7377 1638
jdaggett@7377 1639 <tr>
jdaggett@7377 1640 <td>Animatable:
jdaggett@7377 1641
jdaggett@7377 1642 <td>as <a
jdaggett@7377 1643 href="http://dev.w3.org/csswg/css3-transitions/#animtype-number">number</a>
jdaggett@484 1644 </table>
jdaggett@484 1645
jdaggett@555 1646 <p>For any given font size, the apparent size and legibility of text varies
jdaggett@555 1647 across fonts. For scripts such as Latin or Cyrillic that distinguish
jdaggett@555 1648 between upper and lowercase letters, the relative height of lowercase
jdaggett@555 1649 letters compared to their uppercase counterparts is a determining factor
jdaggett@555 1650 of legibility. This is commonly referred to as the <a class=index-def
jdaggett@4624 1651 href="#aspect-value" id=aspect-value0 title="aspect value"><dfn
jdaggett@4624 1652 id=aspect-value>aspect value</dfn></a>. Precisely defined, it is equal to
jdaggett@4624 1653 the x-height of a font divided by the font size.
jdaggett@555 1654
jdaggett@555 1655 <p>In situations where font fallback occurs, fallback fonts may not share
jdaggett@555 1656 the same aspect ratio as the desired font family and will thus appear less
jdaggett@555 1657 readable. The font-size-adjust property is a way to preserve the
jdaggett@547 1658 readability of text when font fallback occurs. It does this by adjusting
jdaggett@1662 1659 the font-size so that the x-height is the same regardless of the font
jdaggett@555 1660 used.
jdaggett@547 1661
jdaggett@547 1662 <div class=example>
jdaggett@547 1663 <p>The style defined below defines Verdana as the desired font family, but
jdaggett@547 1664 if Verdana is not available Futura or Times will be used.</p>
jdaggett@547 1665
jdaggett@8277 1666 <pre>p {
jdaggett@8277 1667 font-family: Verdana, Futura, Times;
jdaggett@547 1668 }
jdaggett@547 1669
jdaggett@547 1670 &lt;p>Lorem ipsum dolor sit amet, ...&lt;/p>
jdaggett@547 1671 </pre>
jdaggett@547 1672
jdaggett@547 1673 <p>Verdana has a relatively high aspect ratio, lowercase letters are
jdaggett@547 1674 relatively tall compared to uppercase letters, so at small sizes text
jdaggett@547 1675 appears legible. Times has a lower aspect ratio and so if fallback
jdaggett@547 1676 occurs, the text will be less legible at small sizes than Verdana.</p>
jdaggett@547 1677 </div>
jdaggett@547 1678
jdaggett@547 1679 <p>How text rendered in each of these fonts compares is shown below, the
jdaggett@547 1680 columns show text rendered in Verdana, Futura and Times. The same
jdaggett@547 1681 font-size value is used across cells within each row and red lines are
jdaggett@547 1682 included to show the differences in x-height. In the upper half each row
jdaggett@547 1683 is rendered in the same font-size value. The same is true for the lower
jdaggett@547 1684 half but in this half the font-size-adjust property is also set so that
jdaggett@2462 1685 the actual font size is adjusted to preserve the x-height across each row.
jdaggett@547 1686 Note how small text remains relatively legible across each row in the
jdaggett@547 1687 lower half.
jdaggett@547 1688
jdaggett@1150 1689 <div class=figure><img alt="text with and without font-size-adjust"
jdaggett@1150 1690 src=fontsizeadjust.png>
jdaggett@890 1691 <p class=caption>Text with and without the use of font-size-adjust
jdaggett@547 1692 </div>
jdaggett@512 1693
jdaggett@8640 1694 <p>This property allows authors to specify an <a
jdaggett@8640 1695 href="#aspect-value"><i>aspect value</i></a> for an element that will
jdaggett@8640 1696 effectively preserve the x-height of the first choice font, whether it is
jdaggett@8640 1697 substituted or not. Values have the following meanings:
jdaggett@512 1698
jdaggett@512 1699 <dl>
jdaggett@8278 1700 <dt><dfn id=font-size-adjust-none-value
jdaggett@8278 1701 title="none!!font-size-adjust">none</dfn>
jdaggett@512 1702
jdaggett@512 1703 <dd>Do not preserve the font's x-height.
jdaggett@512 1704
jdaggett@8278 1705 <dt><dfn id=font-size-adjust-auto-value
jdaggett@8278 1706 title="auto!!font-size-adjust">auto</dfn>
jdaggett@6659 1707
jdaggett@8640 1708 <dd>Behaves just like &lt;number>, except the number used is the <a
jdaggett@8640 1709 href="#aspect-value"><i>aspect value</i></a> calculated by user agents
jdaggett@8640 1710 for the first font in the list of fonts defined for the initial value of
jdaggett@8640 1711 the <a href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8278 1712 class=property>font-family</code>’</a> property. Effectively this is
jdaggett@8278 1713 the default font used when <a href="#propdef-font-family"
jdaggett@8278 1714 title="font-family!!property">‘<code
jdaggett@8278 1715 class=property>font-family</code>’</a> is not otherwise specified.
jdaggett@6659 1716 <p>Authors can use this value to specify that font size should be
jdaggett@6659 1717 normalized across fonts based on the x-height without the need to
jdaggett@6659 1718 specify the aspect ratio explicitly.</p>
jdaggett@6659 1719
jdaggett@8225 1720 <dt><dfn id=aspect-ratio-value><var>&lt;number&gt;</var></dfn>
jdaggett@512 1721
jdaggett@8640 1722 <dd>Specifies the <a href="#aspect-value"><i>aspect value</i></a> used in
jdaggett@8640 1723 the calculation below to calculate the adjusted font size:
jdaggett@8277 1724 <pre>c = ( a / a' ) s
jdaggett@512 1725 </pre>
jdaggett@512 1726
jdaggett@512 1727 <p>where:</p>
jdaggett@512 1728
jdaggett@554 1729 <pre>s = font-size value
jdaggett@8640 1730 a = <a href="#aspect-value"><i>aspect value</i></a> as specified by the font-size-adjust property
jdaggett@8640 1731 a' = <a href="#aspect-value"><i>aspect value</i></a> of actual font
jdaggett@554 1732 c = adjusted font-size to use
jdaggett@512 1733 </pre>
jdaggett@554 1734
jdaggett@554 1735 <p>This value applies to any font that is selected but in typical usage
jdaggett@8640 1736 it should be based on the <a href="#aspect-value"><i>aspect
jdaggett@8640 1737 value</i></a> of the first font in the font-family list. If this is
jdaggett@8640 1738 specified accurately, the <tt>(a/a')</tt> term in the formula above is
jdaggett@8640 1739 effectively 1 for the first font and no adjustment occurs. If the value
jdaggett@8640 1740 is specified inaccurately, text rendered using the first font in the
jdaggett@8640 1741 family list will display differently in older user agents that don't
jdaggett@8640 1742 support font-size-adjust.</p>
jdaggett@512 1743 </dl>
jdaggett@512 1744
jdaggett@8640 1745 <p>The value of ‘<a href="#propdef-font-size-adjust"><code
jdaggett@8640 1746 class=property>font-size-adjust</code></a>’ affects the size of relative
jdaggett@8640 1747 units that are based on font metrics of the <a
jdaggett@8640 1748 href="#first-available-font"><i>first available font</i></a> such as
jdaggett@8640 1749 <code>ex</code> and <code>ch</code> but does not affect the size of
jdaggett@8640 1750 <code>em</code> units.
jdaggett@8640 1751
jdaggett@8640 1752 <p>Authors can calculate the <a href="#aspect-value"><i>aspect
jdaggett@8640 1753 value</i></a> for a given font by comparing spans with the same content
jdaggett@8640 1754 but different font-size-adjust properties. If the same font-size is used,
jdaggett@8640 1755 the spans will match when the font-size-adjust value is accurate for the
jdaggett@8640 1756 given font.
jdaggett@554 1757
jdaggett@554 1758 <div class=example>
jdaggett@8640 1759 <p>Two spans with borders are used to determine the <a
jdaggett@8640 1760 href="#aspect-value"><i>aspect value</i></a> of a font. The font-size is
jdaggett@8640 1761 the same for both spans but the font-size-adjust property is specified
jdaggett@8640 1762 only for the right span. Starting with a value of 0.5, the aspect value
jdaggett@8640 1763 can be adjusted until the borders around the two letters line up.</p>
jdaggett@554 1764
jdaggett@554 1765 <pre>p {
jdaggett@554 1766 font-family: Futura;
jdaggett@554 1767 font-size: 500px;
jdaggett@554 1768 }
jdaggett@554 1769
jdaggett@554 1770 span {
jdaggett@554 1771 border: solid 1px red;
jdaggett@554 1772 }
jdaggett@554 1773
jdaggett@554 1774 .adjust {
jdaggett@554 1775 font-size-adjust: 0.5;
jdaggett@554 1776 }
jdaggett@554 1777
jdaggett@554 1778 &lt;p>&lt;span>b&lt;/span>&lt;span class="adjust">b&lt;/span>&lt;/p>
jdaggett@554 1779 </pre>
jdaggett@554 1780
jdaggett@8640 1781 <div class=figure><img alt="Futura with an <i>aspect value</i> of 0.5"
jdaggett@1150 1782 src=beforefontsizeadjust.png>
jdaggett@8640 1783 <p class=caption>Futura with an <a href="#aspect-value"><i>aspect
jdaggett@8640 1784 value</i></a> of 0.5
jdaggett@554 1785 </div>
jdaggett@554 1786
jdaggett@554 1787 <p>The box on the right is a bit bigger than the one on the left, so the
jdaggett@8640 1788 <a href="#aspect-value"><i>aspect value</i></a> of this font is something
jdaggett@8640 1789 less than 0.5. Adjust the value until the boxes align.</p>
jdaggett@554 1790 </div>
jdaggett@512 1791 <!-- prop: font -->
jdaggett@512 1792
jdaggett@1662 1793 <h3 id=font-prop><span class=secno>3.7 </span>Shorthand font property: the
jdaggett@1662 1794 <a href="#propdef-font">font</a> property</h3>
jdaggett@1662 1795
jdaggett@8225 1796 <table class=propdef id=namefontvalue-ltlsquofont-stylersquogt-l>
jdaggett@484 1797 <tbody>
jdaggett@484 1798 <tr>
jdaggett@484 1799 <td>Name:
jdaggett@484 1800
jdaggett@1662 1801 <td><dfn id=propdef-font>font</dfn>
jdaggett@484 1802
jdaggett@484 1803 <tr>
jdaggett@484 1804 <td>Value:
jdaggett@484 1805
jdaggett@8278 1806 <td>[ [ <var>&lt;<a href="#propdef-font-style"
jdaggett@8278 1807 title="font-style!!property">‘<code
jdaggett@8278 1808 class=property>font-style</code>’</a>&gt;</var> || <a
jdaggett@8225 1809 href="#font-variant-css21-values"><var>&lt;font-variant-css21&gt;</var></a>
jdaggett@8278 1810 || <var>&lt;<a href="#propdef-font-weight"
jdaggett@8278 1811 title="font-weight!!property">‘<code
jdaggett@8278 1812 class=property>font-weight</code>’</a>&gt;</var> || <var>&lt;<a
jdaggett@8278 1813 href="#propdef-font-stretch" title="font-stretch!!property">‘<code
jdaggett@8278 1814 class=property>font-stretch</code>’</a></var> ]? <var>&lt;‘<a
jdaggett@8225 1815 href="#propdef-font-size"><code
jdaggett@8225 1816 class=property>font-size</code></a>’&gt;</var> [ / <var>&lt;‘<code
jdaggett@8278 1817 class=property>line-height</code>’&gt;</var> ]? <var>&lt;<a
jdaggett@8278 1818 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8278 1819 class=property>font-family</code>’</a>&gt;</var> ] | caption | icon |
jdaggett@8225 1820 menu | message-box | small-caption | status-bar
jdaggett@484 1821
jdaggett@484 1822 <tr>
jdaggett@484 1823 <td>Initial:
jdaggett@484 1824
jdaggett@484 1825 <td>see individual properties
jdaggett@484 1826
jdaggett@484 1827 <tr>
jdaggett@484 1828 <td>Applies to:
jdaggett@484 1829
jdaggett@484 1830 <td>all elements
jdaggett@484 1831
jdaggett@484 1832 <tr>
jdaggett@484 1833 <td>Inherited:
jdaggett@484 1834
jdaggett@484 1835 <td>yes
jdaggett@484 1836
jdaggett@484 1837 <tr>
jdaggett@484 1838 <td>Percentages:
jdaggett@484 1839
jdaggett@484 1840 <td>see individual properties
jdaggett@484 1841
jdaggett@484 1842 <tr>
jdaggett@484 1843 <td>Media:
jdaggett@484 1844
jdaggett@484 1845 <td>visual
jdaggett@484 1846
jdaggett@484 1847 <tr>
jdaggett@1148 1848 <td>Computed value:
jdaggett@484 1849
jdaggett@484 1850 <td>see individual properties
jdaggett@7377 1851
jdaggett@7377 1852 <tr>
jdaggett@7377 1853 <td>Animatable:
jdaggett@7377 1854
jdaggett@7377 1855 <td>see individual properties
jdaggett@484 1856 </table>
jdaggett@1732 1857
jdaggett@4624 1858 <p>The <span class=property>‘<a href="#propdef-font"><code
jdaggett@4624 1859 class=property>font</code></a>’</span> property is, except as described
jdaggett@8278 1860 below, a shorthand property for setting <a href="#propdef-font-style"
jdaggett@8278 1861 title="font-style!!property">‘<code
jdaggett@8278 1862 class=property>font-style</code>’</a>, <a href="#propdef-font-variant"
jdaggett@8278 1863 title="font-variant!!property">‘<code
jdaggett@8278 1864 class=property>font-variant</code>’</a>, <a href="#propdef-font-weight"
jdaggett@8278 1865 title="font-weight!!property">‘<code
jdaggett@8278 1866 class=property>font-weight</code>’</a>, <a href="#propdef-font-stretch"
jdaggett@8278 1867 title="font-stretch!!property">‘<code
jdaggett@8278 1868 class=property>font-stretch</code>’</a>, <span class=property>‘<a
jdaggett@8278 1869 href="#propdef-font-size"><code
jdaggett@8278 1870 class=property>font-size</code></a>’</span>, <a class=property
jdaggett@8278 1871 href="http://www.w3.org/TR/CSS2/visudet.html#propdef-line-height">‘<code
jdaggett@8278 1872 class=property>line-height</code>’</a>, <a href="#propdef-font-family"
jdaggett@8278 1873 title="font-family!!property">‘<code
jdaggett@8278 1874 class=property>font-family</code>’</a> at the same place in the
jdaggett@8278 1875 stylesheet. Values for the <a href="#propdef-font-variant"
jdaggett@8278 1876 title="font-variant!!property">‘<code
jdaggett@8278 1877 class=property>font-variant</code>’</a> property may also be included
jdaggett@8313 1878 but only those supported in CSS 2.1, none of the <a
jdaggett@8313 1879 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8313 1880 class=property>font-variant</code>’</a> values added in this
jdaggett@8313 1881 specification can be used in the <span class=property>‘<a
jdaggett@8278 1882 href="#propdef-font"><code class=property>font</code></a>’</span>
jdaggett@8278 1883 shorthand:
jdaggett@1732 1884
jdaggett@1732 1885 <pre
jdaggett@8225 1886 class=prod><dfn id=font-variant-css21-values><var>&lt;font-variant-css21&gt;</var></dfn> = [normal | small-caps]</pre>
jdaggett@1732 1887
jdaggett@1732 1888 <p>The syntax of this property is based on a traditional typographical
jdaggett@1732 1889 shorthand notation to set multiple properties related to fonts.
jdaggett@512 1890
jdaggett@8197 1891 <p>All subproperties of the ‘<a href="#propdef-font"><code
jdaggett@8197 1892 class=property>font</code></a>’ property are first reset to their
jdaggett@8197 1893 initial values, including those listed above plus <span
jdaggett@4624 1894 class=property>‘<a href="#propdef-font-size-adjust"><code
jdaggett@4624 1895 class=property>font-size-adjust</code></a>’</span>, <span
jdaggett@4624 1896 class=property>‘<a href="#propdef-font-kerning"><code
jdaggett@8278 1897 class=property>font-kerning</code></a>’</span>, subproperties of <a
jdaggett@8278 1898 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8278 1899 class=property>font-variant</code>’</a> and and <span>‘<a
jdaggett@8278 1900 href="#propdef-font-language-override"><code
jdaggett@8197 1901 class=property>font-language-override</code></a>’</span>. Then, those
jdaggett@8197 1902 properties that are given explicit values in the <span
jdaggett@8197 1903 class=property>‘<a href="#propdef-font"><code
jdaggett@4624 1904 class=property>font</code></a>’</span> shorthand are set to those
jdaggett@512 1905 values. For a definition of allowed and initial values, see the previously
jdaggett@512 1906 defined properties. For reasons of backwards compatibility, it is not
jdaggett@4624 1907 possible to set <span class=property>‘<a
jdaggett@7020 1908 href="#propdef-font-size-adjust"><code
jdaggett@7020 1909 class=property>font-size-adjust</code></a>’</span> to anything other
jdaggett@7020 1910 than its initial value using the <span class=property>‘<a
jdaggett@4624 1911 href="#propdef-font"><code class=property>font</code></a>’</span>
jdaggett@7020 1912 shorthand property; instead, use the individual property.
jdaggett@512 1913
jdaggett@512 1914 <div class=example>
jdaggett@8699 1915 <p style="display:none">Example(s):</p>
jdaggett@890 1916
jdaggett@512 1917 <pre>p { font: 12pt/14pt sans-serif }
jdaggett@512 1918 p { font: 80% sans-serif }
jdaggett@512 1919 p { font: x-large/110% &quot;new century schoolbook&quot;, serif }
jdaggett@512 1920 p { font: bold italic large Palatino, serif }
jdaggett@512 1921 p { font: normal small-caps 120%/120% fantasy }
jdaggett@7020 1922 p { font: condensed oblique 12pt &quot;Helvetica Neue&quot;, serif; }
jdaggett@512 1923 </pre>
jdaggett@512 1924
jdaggett@1148 1925 <p> In the second rule, the font size percentage value (‘<code
jdaggett@8187 1926 class=css>80%</code>’) refers to the computed ‘<a
jdaggett@8187 1927 href="#propdef-font-size"><code class=property>font-size</code></a>’ of
jdaggett@8187 1928 the parent element. In the third rule, the line height percentage
jdaggett@8187 1929 (‘<code class=css>110%</code>’) refers to the font size of the
jdaggett@8187 1930 element itself.
jdaggett@512 1931
jdaggett@8278 1932 <p>The first three rules do not specify the <a
jdaggett@8278 1933 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8278 1934 class=property>font-variant</code>’</a> and <a
jdaggett@8278 1935 href="#propdef-font-weight" title="font-weight!!property">‘<code
jdaggett@8278 1936 class=property>font-weight</code>’</a> explicitly, so these properties
jdaggett@8368 1937 receive their initial values (<span title="normal value">‘<code
jdaggett@8368 1938 class=property>normal</code>’</span>). Notice that the font family name
jdaggett@8279 1939 "new century schoolbook", which contains spaces, is enclosed in quotes.
jdaggett@8279 1940 The fourth rule sets the <a href="#propdef-font-weight"
jdaggett@8279 1941 title="font-weight!!property">‘<code
jdaggett@8278 1942 class=property>font-weight</code>’</a> to ‘<a href="#bold"><code
jdaggett@8278 1943 class=property>bold</code></a>’, the <a href="#propdef-font-style"
jdaggett@8278 1944 title="font-style!!property">‘<code
jdaggett@8278 1945 class=property>font-style</code>’</a> to ‘<a href="#italic"><code
jdaggett@8278 1946 class=property>italic</code></a>’, and implicitly sets <a
jdaggett@8278 1947 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8368 1948 class=property>font-variant</code>’</a> to <a
jdaggett@8368 1949 href="#font-variant-normal-value" title="normal!!font-variant">‘<code
jdaggett@8368 1950 class=property>normal</code>’</a>.
jdaggett@8278 1951
jdaggett@8278 1952 <p> The fifth rule sets the <a href="#propdef-font-variant"
jdaggett@8278 1953 title="font-variant!!property">‘<code
jdaggett@8278 1954 class=property>font-variant</code>’</a> (‘<a href="#small-caps"><code
jdaggett@8278 1955 class=property>small-caps</code></a>’), the <span class=property>‘<a
jdaggett@8278 1956 href="#propdef-font-size"><code
jdaggett@4624 1957 class=property>font-size</code></a>’</span> (120% of the parent's font
jdaggett@8278 1958 size), the <a class=property
jdaggett@8278 1959 href="http://www.w3.org/TR/CSS2/visudet.html#propdef-line-height">‘<code
jdaggett@8278 1960 class=property>line-height</code>’</a> (120% of the font size) and the
jdaggett@8278 1961 <a href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8278 1962 class=property>font-family</code>’</a> (‘<a href="#fantasy"><code
jdaggett@8368 1963 class=property>fantasy</code></a>’). It follows that the keyword <span
jdaggett@8368 1964 title="normal value">‘<code class=property>normal</code>’</span>
jdaggett@8368 1965 applies to the two remaining properties: <a href="#propdef-font-style"
jdaggett@8278 1966 title="font-style!!property">‘<code
jdaggett@8278 1967 class=property>font-style</code>’</a> and <a
jdaggett@8278 1968 href="#propdef-font-weight" title="font-weight!!property">‘<code
jdaggett@8278 1969 class=property>font-weight</code>’</a>.
jdaggett@8278 1970
jdaggett@8278 1971 <p>The sixth rule sets the <a href="#propdef-font-style"
jdaggett@8278 1972 title="font-style!!property">‘<code
jdaggett@8278 1973 class=property>font-style</code>’</a>, <a href="#propdef-font-stretch"
jdaggett@8278 1974 title="font-stretch!!property">‘<code
jdaggett@8278 1975 class=property>font-stretch</code>’</a>, <span class=property>‘<a
jdaggett@8278 1976 href="#propdef-font-size"><code
jdaggett@8278 1977 class=property>font-size</code></a>’</span>, and <a
jdaggett@8278 1978 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8278 1979 class=property>font-family</code>’</a>, the other font properties being
jdaggett@8278 1980 set to their initial values.
jdaggett@512 1981 </div>
jdaggett@512 1982
jdaggett@8278 1983 <p>Since the <a href="#propdef-font-stretch"
jdaggett@8278 1984 title="font-stretch!!property">‘<code
jdaggett@8278 1985 class=property>font-stretch</code>’</a> property was not defined in CSS
jdaggett@8278 1986 2.1, when using <a href="#propdef-font-stretch"
jdaggett@8278 1987 title="font-stretch!!property">‘<code
jdaggett@8278 1988 class=property>font-stretch</code>’</a> values within ‘<a
jdaggett@7020 1989 href="#propdef-font"><code class=property>font</code></a>’ rules,
jdaggett@7020 1990 authors should include a extra version compatible with older user agents:
jdaggett@7020 1991
jdaggett@7020 1992 <pre>p {
jdaggett@7020 1993 font: 80% sans-serif; /* for older user agents */
jdaggett@7020 1994 font: condensed 80% sans-serif;
jdaggett@7020 1995 }</pre>
jdaggett@7020 1996
jdaggett@1662 1997 <p>The following values refer to system fonts:
jdaggett@512 1998
jdaggett@512 1999 <dl>
jdaggett@512 2000 <dt><strong>caption</strong>
jdaggett@512 2001
jdaggett@512 2002 <dd>The font used for captioned controls (e.g., buttons, drop-downs,
jdaggett@512 2003 etc.).
jdaggett@512 2004
jdaggett@512 2005 <dt><strong>icon</strong>
jdaggett@512 2006
jdaggett@512 2007 <dd>The font used to label icons.
jdaggett@512 2008
jdaggett@512 2009 <dt><strong>menu</strong>
jdaggett@512 2010
jdaggett@512 2011 <dd>The font used in menus (e.g., dropdown menus and menu lists).
jdaggett@512 2012
jdaggett@512 2013 <dt><strong>message-box</strong>
jdaggett@512 2014
jdaggett@512 2015 <dd>The font used in dialog boxes.
jdaggett@512 2016
jdaggett@512 2017 <dt><strong>small-caption</strong>
jdaggett@512 2018
jdaggett@512 2019 <dd>The font used for labeling small controls.
jdaggett@512 2020
jdaggett@512 2021 <dt><strong>status-bar</strong>
jdaggett@512 2022
jdaggett@512 2023 <dd>The font used in window status bars.
jdaggett@512 2024 </dl>
jdaggett@512 2025
jdaggett@512 2026 <p>System fonts may only be set as a whole; that is, the font family, size,
jdaggett@1662 2027 weight, style, etc. are all set at the same time. These values may then be
jdaggett@512 2028 altered individually if desired. If no font with the indicated
jdaggett@512 2029 characteristics exists on a given platform, the user agent should either
jdaggett@1148 2030 intelligently substitute (e.g., a smaller version of the ‘<code
jdaggett@1148 2031 class=property>caption</code>’ font might be used for the ‘<code
jdaggett@7242 2032 class=property>small-caption</code>’ font), or substitute a user agent
jdaggett@1148 2033 default font. As for regular fonts, if, for a system font, any of the
jdaggett@1148 2034 individual properties are not part of the operating system's available
jdaggett@1148 2035 user preferences, those properties should be set to their initial values.
jdaggett@512 2036
jdaggett@1662 2037 <p>That is why this property is "almost" a shorthand property: system fonts
jdaggett@8278 2038 can only be specified with this property, not with <a
jdaggett@8278 2039 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8278 2040 class=property>font-family</code>’</a> itself, so <span
jdaggett@4624 2041 class=property>‘<a href="#propdef-font"><code
jdaggett@4624 2042 class=property>font</code></a>’</span> allows authors to do more than
jdaggett@4624 2043 the sum of its subproperties. However, the individual properties such as
jdaggett@8278 2044 <a href="#propdef-font-weight" title="font-weight!!property">‘<code
jdaggett@8278 2045 class=property>font-weight</code>’</a> are still given values taken from
jdaggett@8278 2046 the system font, which can be independently varied.
jdaggett@512 2047
jdaggett@7235 2048 <p>Note that the keywords used for the system fonts listed above are only
jdaggett@7235 2049 treated as keywords when they occur in the initial position, in other
jdaggett@7235 2050 positions the same string is treated as part of the font family name:
jdaggett@7235 2051
jdaggett@7235 2052 <pre> font: menu; /* use the font settings for system menus */
jdaggett@7235 2053 font: large menu; /* use a font family named "menu" */</pre>
jdaggett@7235 2054
jdaggett@512 2055 <div class=example>
jdaggett@8699 2056 <p style="display:none">Example(s):</p>
jdaggett@890 2057
jdaggett@512 2058 <pre>button { font: 300 italic 1.3em/1.7em &quot;FB Armada&quot;, sans-serif }
jdaggett@512 2059 button p { font: menu }
jdaggett@512 2060 button p em { font-weight: bolder }
jdaggett@512 2061 </pre>
jdaggett@512 2062
jdaggett@512 2063 <p>If the font used for dropdown menus on a particular system happened to
jdaggett@512 2064 be, for example, 9-point Charcoal, with a weight of 600, then P elements
jdaggett@512 2065 that were descendants of BUTTON would be displayed as if this rule were
jdaggett@890 2066 in effect:
jdaggett@512 2067
jdaggett@512 2068 <pre>button p { font: 600 9pt Charcoal }
jdaggett@512 2069 </pre>
jdaggett@512 2070
jdaggett@4624 2071 <p>Because the <span class=property>‘<a href="#propdef-font"><code
jdaggett@4624 2072 class=property>font</code></a>’</span> shorthand resets to its initial
jdaggett@4624 2073 value any property not explicitly given a value, this has the same effect
jdaggett@4624 2074 as this declaration:
jdaggett@512 2075
jdaggett@512 2076 <pre>button p {
jdaggett@512 2077 font-style: normal;
jdaggett@512 2078 font-variant: normal;
jdaggett@512 2079 font-weight: 600;
jdaggett@512 2080 font-size: 9pt;
jdaggett@512 2081 line-height: normal;
jdaggett@512 2082 font-family: Charcoal
jdaggett@8277 2083 }
jdaggett@512 2084 </pre>
jdaggett@512 2085 </div>
jdaggett@2487 2086 <!-- prop: font-synthesis -->
jdaggett@2487 2087
jdaggett@2487 2088 <h3 id=font-synthesis-prop><span class=secno>3.8 </span>Controlling
jdaggett@2487 2089 synthetic faces: the <a href="#propdef-font-synthesis">font-synthesis</a>
jdaggett@2487 2090 property</h3>
jdaggett@2487 2091
jdaggett@4624 2092 <table class=propdef id=namefont-synthesisvaluenone-weight-style>
jdaggett@2457 2093 <tbody>
jdaggett@2457 2094 <tr>
jdaggett@2457 2095 <td>Name:
jdaggett@2457 2096
jdaggett@2487 2097 <td><dfn id=propdef-font-synthesis>font-synthesis</dfn>
jdaggett@2457 2098
jdaggett@2457 2099 <tr>
jdaggett@2457 2100 <td>Value:
jdaggett@2457 2101
jdaggett@2487 2102 <td>none | [ weight || style ]
jdaggett@2457 2103
jdaggett@2457 2104 <tr>
jdaggett@2457 2105 <td>Initial:
jdaggett@2457 2106
jdaggett@2487 2107 <td>weight style
jdaggett@2457 2108
jdaggett@2457 2109 <tr>
jdaggett@2457 2110 <td>Applies to:
jdaggett@2457 2111
jdaggett@2457 2112 <td>all elements
jdaggett@2457 2113
jdaggett@2457 2114 <tr>
jdaggett@2457 2115 <td>Inherited:
jdaggett@2457 2116
jdaggett@2457 2117 <td>yes
jdaggett@2457 2118
jdaggett@2457 2119 <tr>
jdaggett@2457 2120 <td>Percentages:
jdaggett@2457 2121
jdaggett@2457 2122 <td>N/A
jdaggett@2457 2123
jdaggett@2457 2124 <tr>
jdaggett@2457 2125 <td>Media:
jdaggett@2457 2126
jdaggett@2457 2127 <td>visual
jdaggett@2457 2128
jdaggett@2457 2129 <tr>
jdaggett@2457 2130 <td>Computed value:
jdaggett@2457 2131
jdaggett@2457 2132 <td>as specified
jdaggett@7377 2133
jdaggett@7377 2134 <tr>
jdaggett@7377 2135 <td>Animatable:
jdaggett@7377 2136
jdaggett@7377 2137 <td>no
jdaggett@2457 2138 </table>
jdaggett@2457 2139
jdaggett@2487 2140 <p>This property controls whether user agents are allowed to synthesize
jdaggett@2487 2141 bold or oblique font faces when a font family lacks bold or italic faces.
jdaggett@7311 2142 If ‘<a href="#weight"><code class=property>weight</code></a>’ is not
jdaggett@7311 2143 specified, user agents must not synthesize bold faces and if ‘<code
jdaggett@2487 2144 class=property>style</code>’ is not specified user agents must not
jdaggett@8278 2145 synthesize italic faces. A value of ‘<code class=property>none</code>’
jdaggett@8278 2146 disallows all synthetic faces.
jdaggett@2457 2147
jdaggett@2457 2148 <div class=example>
jdaggett@2488 2149 <p>The style rule below disables the use of synthetically obliqued Arabic:</p>
jdaggett@2457 2150
jdaggett@2487 2151 <pre>*:lang(ar) { font-synthesis: none; }
jdaggett@2457 2152 </pre>
jdaggett@2457 2153 </div>
jdaggett@512 2154
jdaggett@6699 2155 <h2 id=font-resources><span class=secno>4 </span>Font Resources</h2>
jdaggett@545 2156
jdaggett@8311 2157 <h3 id=font-face-rule><span class=secno>4.1 </span>The <dfn
jdaggett@8311 2158 id=at-font-face-rule style="font-weight: inherit; font-style:
jdaggett@8311 2159 inherit"><code>@font-face</code></dfn> rule</h3>
jdaggett@8311 2160
jdaggett@8311 2161 <p>The <a href="#at-font-face-rule"><code>@font-face</code></a> rule allows
jdaggett@8311 2162 for linking to fonts that are automatically fetched and activated when
jdaggett@8311 2163 needed. This allows authors to select a font that closely matches the
jdaggett@8311 2164 design goals for a given page rather than limiting the font choice to a
jdaggett@8311 2165 set of fonts available on all platforms. A set of font descriptors define
jdaggett@8311 2166 the location of a font resource, either locally or externally, along with
jdaggett@8311 2167 the style characteristics of an individual face. Multiple <a
jdaggett@8311 2168 href="#at-font-face-rule"><code>@font-face</code></a> rules can be used to
jdaggett@8311 2169 construct font families with a variety of faces. Using CSS font matching
jdaggett@8311 2170 rules, a user agent can selectively download only those faces that are
jdaggett@8311 2171 needed for a given piece of text.
jdaggett@8311 2172
jdaggett@8311 2173 <p>The <a href="#at-font-face-rule"><code>@font-face</code></a> rule
jdaggett@8311 2174 consists of the <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2175 at-keyword followed by a block of descriptor declarations. In terms of the
jdaggett@8311 2176 grammar, this specification defines the following productions:
jdaggett@8031 2177
jdaggett@8031 2178 <pre><dfn id=fontfacerule>font_face_rule</dfn>
jdaggett@8225 2179 : <a href="#fontfacesym"><i>FONT_FACE_SYM</i></a> <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* '{' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#descriptordeclaration"><i>descriptor_declaration</i></a>? [ ';' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#descriptordeclaration"><i>descriptor_declaration</i></a>? ]* '}' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>*
jdaggett@8031 2180 ;
jdaggett@8031 2181
jdaggett@8031 2182 <dfn id=descriptordeclaration>descriptor_declaration</dfn>
jdaggett@8225 2183 : <a href="http://www.w3.org/TR/CSS21/grammar.html#grammar"><i>property</i></a> ':' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="http://www.w3.org/TR/CSS21/grammar.html#grammar"><i>expr</i></a>
jdaggett@8031 2184 ;</pre>
jdaggett@8031 2185
jdaggett@8032 2186 <p>The following new definitions are introduced:
jdaggett@8032 2187
jdaggett@8032 2188 <pre>- -|\\0{0,4}2d(\r\n|[ \t\r\n\f])?
jdaggett@8032 2189 F f|\\0{0,4}(46|66)(\r\n|[ \t\r\n\f])?</pre>
jdaggett@8032 2190
jdaggett@8032 2191 <p>The following new token is introduced:
jdaggett@8032 2192
jdaggett@8225 2193 <pre>@{F}{O}{N}{T}{-}{F}{A}{C}{E} {return <dfn id=fontfacesym>FONT_FACE_SYM</dfn>;}</pre>
jdaggett@8032 2194
jdaggett@8311 2195 <p>Each <a href="#at-font-face-rule"><code>@font-face</code></a> rule
jdaggett@8311 2196 specifies a value for every font descriptor, either implicitly or
jdaggett@8311 2197 explicitly. Those not given explicit values in the rule take the initial
jdaggett@8311 2198 value listed with each descriptor in this specification. These descriptors
jdaggett@8311 2199 apply solely within the context of the <a
jdaggett@8311 2200 href="#at-font-face-rule"><code>@font-face</code></a> rule in which they
jdaggett@8311 2201 are defined, and do not apply to document language elements. There is no
jdaggett@8311 2202 notion of which elements the descriptors apply to or whether the values
jdaggett@8311 2203 are inherited by child elements. When a given descriptor occurs multiple
jdaggett@8311 2204 times in a given <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2205 rule, only the last descriptor declaration is used and all prior
jdaggett@8311 2206 declarations for that descriptor are ignored.
jdaggett@512 2207
jdaggett@525 2208 <div class=example>
jdaggett@525 2209 <p>To use a downloadable font called Gentium:</p>
jdaggett@512 2210
jdaggett@512 2211 <pre>
jdaggett@525 2212 @font-face {
jdaggett@525 2213 font-family: Gentium;
jdaggett@2556 2214 src: url(http://example.com/fonts/Gentium.ttf);
jdaggett@525 2215 }
jdaggett@525 2216
jdaggett@525 2217 p { font-family: Gentium, serif; }
jdaggett@512 2218 </pre>
jdaggett@512 2219
jdaggett@573 2220 <p>The user agent will download Gentium and use it when rendering text
jdaggett@573 2221 within paragraph elements. If for some reason the site serving the font
jdaggett@573 2222 is unavailable, the default serif font will be used.</p>
jdaggett@512 2223 </div>
jdaggett@512 2224
jdaggett@8311 2225 <p>A given set of <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2226 rules define a set of fonts available for use within the documents that
jdaggett@8311 2227 contain these rules. When font matching is done, fonts defined using these
jdaggett@8311 2228 rules are considered before other available fonts on a system.
jdaggett@8198 2229
jdaggett@8198 2230 <p>Downloaded fonts are only available to documents that reference them.
jdaggett@8198 2231 The process of activating these fonts must not make them available to
jdaggett@2472 2232 other applications or to documents that don't directly link to the same
jdaggett@2556 2233 font. User agent implementers might consider it convenient to use
jdaggett@2472 2234 downloaded fonts when rendering characters in other documents for which no
jdaggett@8363 2235 other available font exists as part of the <a
jdaggett@8363 2236 href="#system-font-fallback"><em>system font fallback</em></a> procedure.
jdaggett@8198 2237 However, this would cause a security leak since the contents of one page
jdaggett@8198 2238 would be able to affect other pages, something an attacker could use as an
jdaggett@8198 2239 attack vector. These restrictions do not affect caching behavior, fonts
jdaggett@8198 2240 are cached the same way other web resources are cached.
jdaggett@8198 2241
jdaggett@8198 2242 <p>This at-rule follows the forward-compatible parsing rules of CSS. Like
jdaggett@8198 2243 properties in a declaration block, declarations of any descriptors that
jdaggett@8311 2244 are not supported by the user agent must be ignored. <a
jdaggett@8311 2245 href="#at-font-face-rule"><code>@font-face</code></a> rules require a
jdaggett@8311 2246 font-family and src descriptor; if either of these are missing, the <a
jdaggett@8311 2247 href="#at-font-face-rule"><code>@font-face</code></a> rule is invalid and
jdaggett@8311 2248 must be ignored entirely.
jdaggett@1244 2249
jdaggett@1244 2250 <p>In cases where user agents have limited platform resources or implement
jdaggett@8311 2251 the ability to disable downloadable font resources, <a
jdaggett@8311 2252 href="#at-font-face-rule"><code>@font-face</code></a> rules must simply be
jdaggett@8311 2253 ignored; the behavior of individual descriptors as defined in this
jdaggett@8311 2254 specification should not be altered.
jdaggett@1662 2255
jdaggett@1662 2256 <h3 id=font-family-desc><span class=secno>4.2 </span>Font family: the <a
jdaggett@1662 2257 href="#descdef-font-family">font-family</a> descriptor</h3>
jdaggett@512 2258
jdaggett@512 2259 <table class=descdef>
jdaggett@512 2260 <tbody>
jdaggett@512 2261 <tr>
jdaggett@512 2262 <td>Name:
jdaggett@512 2263
jdaggett@8278 2264 <td><dfn id=descdef-font-family
jdaggett@8278 2265 title="font-family!!descriptor">font-family</dfn>
jdaggett@512 2266
jdaggett@512 2267 <tr>
jdaggett@512 2268 <td>Value:
jdaggett@512 2269
jdaggett@8225 2270 <td><a href="#family-name-value"><var>&lt;family-name&gt;</var></a>
jdaggett@890 2271
jdaggett@890 2272 <tr>
jdaggett@890 2273 <td><em>Initial:</em>
jdaggett@890 2274
jdaggett@890 2275 <td>N/A
jdaggett@512 2276 </table>
jdaggett@512 2277
jdaggett@525 2278 <p>This descriptor defines the font family name that will be used in all
jdaggett@8311 2279 CSS font family name matching. It is required for the <a
jdaggett@8311 2280 href="#at-font-face-rule"><code>@font-face</code></a> rule to be valid. It
jdaggett@8311 2281 overrides the font family names contained in the underlying font data. If
jdaggett@8311 2282 the font family name is the same as a font family available in a given
jdaggett@8311 2283 user's environment, it effectively hides the underlying font for documents
jdaggett@8311 2284 that use the stylesheet. This permits a web author to freely choose
jdaggett@8311 2285 font-family names without worrying about conflicts with font family names
jdaggett@8311 2286 present in a given user's environment. Likewise, platform substitutions
jdaggett@8311 2287 for a given font family name must not be used.
jdaggett@1244 2288
jdaggett@1662 2289 <h3 id=src-desc><span class=secno>4.3 </span>Font reference: the <a
jdaggett@1662 2290 href="#descdef-src">src</a> descriptor</h3>
jdaggett@512 2291
jdaggett@512 2292 <table class=descdef>
jdaggett@512 2293 <tbody>
jdaggett@512 2294 <tr>
jdaggett@512 2295 <td>Name:
jdaggett@512 2296
jdaggett@1662 2297 <td><dfn id=descdef-src>src</dfn>
jdaggett@512 2298
jdaggett@512 2299 <tr>
jdaggett@512 2300 <td>Value:
jdaggett@512 2301
jdaggett@8225 2302 <td>[ &lt;url> [format(&lt;string> #)]? | <a
jdaggett@8225 2303 href="#font-face-name-value"><var>&lt;font-face-name&gt;</var></a> ] #
jdaggett@890 2304
jdaggett@890 2305 <tr>
jdaggett@890 2306 <td><em>Initial:</em>
jdaggett@890 2307
jdaggett@890 2308 <td>N/A
jdaggett@512 2309 </table>
jdaggett@512 2310
jdaggett@899 2311 <p>This descriptor specifies the resource containing font data. It is
jdaggett@8311 2312 required for the <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2313 rule to be valid. Its value is a prioritized, comma-separated list of
jdaggett@8311 2314 external references or locally-installed font face names. When a font is
jdaggett@8311 2315 needed the user agent iterates over the set of references listed, using
jdaggett@8311 2316 the first one it can successfully activate. Fonts containing invalid data
jdaggett@8311 2317 or local font faces that are not found are ignored and the user agent
jdaggett@8311 2318 loads the next font in the list.
jdaggett@8272 2319
jdaggett@8272 2320 <p>As with other URLs in CSS, the URL may be relative, in which case it is
jdaggett@8311 2321 resolved relative to the location of the style sheet containing the <a
jdaggett@8311 2322 href="#at-font-face-rule"><code>@font-face</code></a> rule. In the case of
jdaggett@8311 2323 SVG fonts, the URL points to an element within a document containing SVG
jdaggett@8311 2324 font definitions. If the element reference is omitted, a reference to the
jdaggett@8311 2325 first defined font is implied. Similarly, font container formats that can
jdaggett@7096 2326 contain more than one font must load one and only one of the fonts for a
jdaggett@8311 2327 given <a href="#at-font-face-rule"><code>@font-face</code></a> rule.
jdaggett@8311 2328 Fragment identifiers are used to indicate which font to load. If a
jdaggett@8311 2329 container format lacks a defined fragment identifier scheme,
jdaggett@8311 2330 implementations should use a simple 1-based indexing scheme (e.g.
jdaggett@8311 2331 "font-collection#1" for the first font, "font-collection#2" for the second
jdaggett@8311 2332 font).
jdaggett@1244 2333
jdaggett@2527 2334 <pre>
jdaggett@2527 2335 src: url(fonts/simple.ttf); /* load simple.ttf relative to stylesheet location */
jdaggett@2527 2336 src: url(/fonts/simple.ttf); /* load simple.ttf from absolute location */
jdaggett@2527 2337 src: url(fonts.svg#simple); /* load SVG font with id 'simple' */
jdaggett@2527 2338 </pre>
jdaggett@2527 2339
jdaggett@8198 2340 <p>External references consist of a URL, followed by an optional hint
jdaggett@8198 2341 describing the format of the font resource referenced by that URL. The
jdaggett@2527 2342 format hint contains a comma-separated list of format strings that denote
jdaggett@2527 2343 well-known font formats. Conformant user agents must skip downloading a
jdaggett@2527 2344 font resource if the format hints indicate only unsupported or unknown
jdaggett@2527 2345 font formats. If no format hints are supplied, the user agent should
jdaggett@2527 2346 download the font resource.
jdaggett@2527 2347
jdaggett@2527 2348 <pre>
jdaggett@2527 2349 /* load WOFF font if possible, otherwise use OpenType font */
jdaggett@2527 2350 @font-face {
jdaggett@2527 2351 font-family: bodytext;
jdaggett@2527 2352 src: url(ideal-sans-serif.woff) format("woff"),
jdaggett@2527 2353 url(basic-sans-serif.ttf) format("opentype");
jdaggett@2527 2354 }
jdaggett@2527 2355 </pre>
jdaggett@2527 2356
jdaggett@2527 2357 <p>Format strings defined by this specification:
jdaggett@2527 2358
jdaggett@2527 2359 <table class=data id=fontformats>
jdaggett@2527 2360 <thead>
jdaggett@2527 2361 <tr>
jdaggett@2527 2362 <th>String
jdaggett@2527 2363
jdaggett@2527 2364 <th>Font Format
jdaggett@2527 2365
jdaggett@2527 2366 <th>Common extensions
jdaggett@2527 2367
jdaggett@2527 2368 <tbody>
jdaggett@2527 2369 <tr>
jdaggett@2527 2370 <th>"woff"
jdaggett@2527 2371
jdaggett@4624 2372 <td><a href="http://www.w3.org/TR/WOFF/">WOFF (Web Open Font Format)</a>
jdaggett@2527 2373
jdaggett@2527 2374 <td>.woff
jdaggett@2527 2375
jdaggett@2527 2376 <tr>
jdaggett@2527 2377 <th>"truetype"
jdaggett@2527 2378
jdaggett@4624 2379 <td><a
jdaggett@4624 2380 href="http://www.microsoft.com/typography/otspec/default.htm">TrueType</a>
jdaggett@2527 2381
jdaggett@2527 2382 <td>.ttf
jdaggett@2527 2383
jdaggett@2527 2384 <tr>
jdaggett@2527 2385 <th>"opentype"
jdaggett@2527 2386
jdaggett@4624 2387 <td><a
jdaggett@4624 2388 href="http://www.microsoft.com/typography/otspec/default.htm">OpenType</a>
jdaggett@2527 2389
jdaggett@2527 2390 <td>.ttf, .otf
jdaggett@2527 2391
jdaggett@2527 2392 <tr>
jdaggett@2527 2393 <th>"embedded-opentype"
jdaggett@2527 2394
jdaggett@4624 2395 <td><a
jdaggett@4624 2396 href="http://www.w3.org/Submission/2008/SUBM-EOT-20080305/">Embedded
jdaggett@4624 2397 OpenType</a>
jdaggett@2527 2398
jdaggett@2527 2399 <td>.eot
jdaggett@2527 2400
jdaggett@2527 2401 <tr>
jdaggett@2527 2402 <th>"svg"
jdaggett@2527 2403
jdaggett@4624 2404 <td><a href="http://www.w3.org/TR/SVG/fonts.html">SVG Font</a>
jdaggett@2527 2405
jdaggett@2527 2406 <td>.svg, .svgz
jdaggett@2527 2407 </table>
jdaggett@2527 2408
jdaggett@2527 2409 <p>Given the overlap in common usage between TrueType and OpenType, the
jdaggett@2527 2410 format hints "truetype" and "opentype" must be considered as synonymous; a
jdaggett@2527 2411 format hint of "opentype" does not imply that the font contains Postscript
jdaggett@2527 2412 CFF style glyph data or that it contains OpenType layout information (see
jdaggett@7377 2413 <a href="#platform-props-to-css">Appendix A</a> for more background on
jdaggett@7377 2414 this).
jdaggett@2527 2415
jdaggett@2527 2416 <p>When authors would prefer to use a locally available copy of a given
jdaggett@8198 2417 font and download it if it's not, <code>local()</code> can be used. The
jdaggett@8225 2418 locally-installed <dfn
jdaggett@8225 2419 id=font-face-name-value><var>&lt;font-face-name&gt;</var></dfn> argument
jdaggett@8272 2420 to <code>local()</code> is a format-specific string that uniquely
jdaggett@8272 2421 identifies a single font face within a larger family. The syntax for a <a
jdaggett@8225 2422 href="#font-face-name-value"><var>&lt;font-face-name&gt;</var></a> is a
jdaggett@8241 2423 unique font face name enclosed by "local(" and ")". The name can
jdaggett@8241 2424 optionally be enclosed in quotes. If unquoted, the unquoted font family
jdaggett@8241 2425 name processing conventions apply; the name must be a sequence of
jdaggett@8241 2426 identifiers separated by whitespace which is converted to a string by
jdaggett@8241 2427 joining the identifiers together separated by a single space.
jdaggett@2527 2428
jdaggett@2527 2429 <pre>
jdaggett@2527 2430 /* regular face of Gentium */
jdaggett@573 2431 @font-face {
jdaggett@2527 2432 font-family: MyGentium;
jdaggett@2527 2433 src: local(Gentium), /* use locally available Gentium */
jdaggett@2527 2434 url(Gentium.ttf); /* otherwise, download it */
jdaggett@573 2435 }
jdaggett@573 2436 </pre>
jdaggett@573 2437
jdaggett@8241 2438 <p>For OpenType and TrueType fonts, this string is used to match only the
jdaggett@8241 2439 Postscript name or the full font name in the name table of locally
jdaggett@8241 2440 available fonts. Which type of name is used varies by platform and font,
jdaggett@8241 2441 so authors should include both of these names to assure proper matching
jdaggett@8241 2442 across platforms. Platform substitutions for a given font name must not be
jdaggett@8241 2443 used.
jdaggett@2527 2444
jdaggett@2527 2445 <pre>
jdaggett@2527 2446 /* bold face of Gentium */
jdaggett@2527 2447 @font-face {
jdaggett@2527 2448 font-family: MyGentium;
jdaggett@2527 2449 src: local(Gentium Bold), /* full font name */
jdaggett@2527 2450 local(Gentium-Bold), /* Postscript name */
jdaggett@2527 2451 url(GentiumBold.ttf); /* otherwise, download it */
jdaggett@2527 2452 font-weight: bold;
jdaggett@2527 2453 }
jdaggett@2527 2454 </pre>
jdaggett@2527 2455
jdaggett@8311 2456 <p>Just as a <a href="#at-font-face-rule"><code>@font-face</code></a> rule
jdaggett@8311 2457 specifies the characteristics of a single font within a family, the unique
jdaggett@8311 2458 name used with <code>local()</code> specifies a single font, not an entire
jdaggett@8311 2459 font family. Defined in terms of OpenType font data, the Postscript name
jdaggett@8311 2460 is found in the font's <a
jdaggett@2527 2461 href="http://www.microsoft.com/typography/otspec/name.htm">name table</a>,
jdaggett@2527 2462 in the name record with nameID = 6 (see <a href="#OPENTYPE"
jdaggett@2556 2463 rel=biblioentry>[OPENTYPE]<!--{{!OPENTYPE}}--></a> for more details). The
jdaggett@2527 2464 Postscript name is the commonly used key for all fonts on OSX and for
jdaggett@2527 2465 Postscript CFF fonts under Windows. The full font name (nameID = 4) is
jdaggett@2527 2466 used as a unique key for fonts with TrueType glyphs on Windows.
jdaggett@2527 2467
jdaggett@2527 2468 <p>For OpenType fonts with multiple localizations of the full font name,
jdaggett@2527 2469 the US English version is used (language ID = 0x409 for Windows and
jdaggett@2527 2470 language ID = 0 for Macintosh) or the first localization when a US English
jdaggett@2527 2471 full font name is not available (the OpenType specification recommends
jdaggett@2527 2472 that <a href="http://www.microsoft.com/typography/otspec/recom.htm">all
jdaggett@2527 2473 fonts minimally include US English names</a>). User agents that also match
jdaggett@2527 2474 other full font names, e.g. matching the Dutch name when the current
jdaggett@2527 2475 system locale is set to Dutch, are considered non-conformant. This is done
jdaggett@2527 2476 not to prefer English but to avoid matching inconsistencies across font
jdaggett@2527 2477 versions and OS localizations, since font style names (e.g. "Bold") are
jdaggett@2527 2478 frequently localized into many languages and the set of localizations
jdaggett@2527 2479 available varies widely across platform and font version. User agents that
jdaggett@2527 2480 match a concatenation of family name (nameID = 1) with style name (nameID
jdaggett@2527 2481 = 2) are considered non-conformant.
jdaggett@2527 2482
jdaggett@2527 2483 <p>This also allows for referencing faces that belong to larger families
jdaggett@2527 2484 that cannot otherwise be referenced.
jdaggett@2527 2485
jdaggett@2527 2486 <div class=example>
jdaggett@525 2487 <p>Use a local font or reference an SVG font in another document:</p>
jdaggett@525 2488
jdaggett@525 2489 <pre>
jdaggett@525 2490 @font-face {
jdaggett@525 2491 font-family: Headline;
jdaggett@8277 2492 src: local(Futura-Medium),
jdaggett@1148 2493 url(fonts.svg#MyGeometricModern) format("svg");
jdaggett@525 2494 }
jdaggett@525 2495 </pre>
jdaggett@525 2496
jdaggett@525 2497 <p>Create an alias for local Japanese fonts on different platforms:</p>
jdaggett@525 2498
jdaggett@525 2499 <pre>
jdaggett@525 2500 @font-face {
jdaggett@2527 2501 font-family: jpgothic;
jdaggett@525 2502 src: local(HiraKakuPro-W3), local(Meiryo), local(IPAPGothic);
jdaggett@525 2503 }
jdaggett@525 2504 </pre>
jdaggett@525 2505
jdaggett@525 2506 <p>Reference a font face that cannot be matched within a larger family:</p>
jdaggett@525 2507
jdaggett@525 2508 <pre>
jdaggett@525 2509 @font-face {
jdaggett@525 2510 font-family: Hoefler Text Ornaments;
jdaggett@525 2511 /* has the same font properties as Hoefler Text Regular */
jdaggett@8277 2512 src: local(HoeflerText-Ornaments);
jdaggett@525 2513 }
jdaggett@525 2514 </pre>
jdaggett@2527 2515
jdaggett@8198 2516 <p>Since localized fullnames never match, a document with the header style
jdaggett@8198 2517 rules below would always render using the default serif font, regardless
jdaggett@8198 2518 whether a particular system locale parameter is set to Finnish or not:</p>
jdaggett@1662 2519
jdaggett@1662 2520 <pre>
jdaggett@1662 2521 @font-face {
jdaggett@1662 2522 font-family: SectionHeader;
jdaggett@6653 2523 src: local("Arial Lihavoitu"); /* Finnish fullname for Arial Bold, should fail */
jdaggett@1662 2524 font-weight: bold;
jdaggett@1662 2525 }
jdaggett@1662 2526
jdaggett@1662 2527 h2 { font-family: SectionHeader, serif; }
jdaggett@1662 2528 </pre>
jdaggett@1662 2529
jdaggett@8198 2530 <p>A conformant user agent would never load the font ‘<code
jdaggett@1662 2531 class=css>gentium.eot</code>’ in the example below, since it is
jdaggett@4624 2532 included in the first definition of the ‘<a href="#descdef-src"><code
jdaggett@4624 2533 class=property>src</code></a>’ descriptor which is overridden by the
jdaggett@8311 2534 second definition in the same <a
jdaggett@8311 2535 href="#at-font-face-rule"><code>@font-face</code></a> rule:</p>
jdaggett@1662 2536
jdaggett@1662 2537 <pre>
jdaggett@1662 2538 @font-face {
jdaggett@1662 2539 font-family: MainText;
jdaggett@6653 2540 src: url(gentium.eot); /* for use with older non-conformant user agents */
jdaggett@1662 2541 src: local("Gentium"), url(gentium.ttf); /* Overrides src definition */
jdaggett@1662 2542 }
jdaggett@1662 2543 </pre>
jdaggett@1662 2544 </div>
jdaggett@1662 2545
jdaggett@1662 2546 <h3 id=font-prop-desc><span class=secno>4.4 </span>Font property
jdaggett@1662 2547 descriptors: the <a href="#descdef-font-style">font-style</a>, <a
jdaggett@1662 2548 href="#descdef-font-weight">font-weight</a>, <a
jdaggett@1662 2549 href="#descdef-font-stretch">font-stretch</a> descriptors</h3>
jdaggett@518 2550
jdaggett@518 2551 <table class=descdef>
jdaggett@518 2552 <tbody>
jdaggett@518 2553 <tr>
jdaggett@518 2554 <td>Name:
jdaggett@518 2555
jdaggett@8278 2556 <td><dfn id=descdef-font-style
jdaggett@8278 2557 title="font-style!!descriptor">font-style</dfn>
jdaggett@518 2558
jdaggett@518 2559 <tr>
jdaggett@518 2560 <td>Value:
jdaggett@518 2561
jdaggett@545 2562 <td>normal | italic | oblique
jdaggett@890 2563
jdaggett@890 2564 <tr>
jdaggett@890 2565 <td><em>Initial:</em>
jdaggett@890 2566
jdaggett@890 2567 <td>normal
jdaggett@518 2568 </table>
jdaggett@518 2569
jdaggett@518 2570 <table class=descdef>
jdaggett@518 2571 <tbody>
jdaggett@518 2572 <tr>
jdaggett@518 2573 <td>Name:
jdaggett@518 2574
jdaggett@8278 2575 <td><dfn id=descdef-font-weight
jdaggett@8278 2576 title="font-weight!!descriptor">font-weight</dfn>
jdaggett@518 2577
jdaggett@518 2578 <tr>
jdaggett@518 2579 <td>Value:
jdaggett@518 2580
jdaggett@545 2581 <td>normal | bold | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900
jdaggett@890 2582
jdaggett@890 2583 <tr>
jdaggett@890 2584 <td><em>Initial:</em>
jdaggett@890 2585
jdaggett@890 2586 <td>normal
jdaggett@518 2587 </table>
jdaggett@518 2588
jdaggett@518 2589 <table class=descdef>
jdaggett@518 2590 <tbody>
jdaggett@518 2591 <tr>
jdaggett@518 2592 <td>Name:
jdaggett@518 2593
jdaggett@8278 2594 <td><dfn id=descdef-font-stretch
jdaggett@8278 2595 title="font-stretch!!descriptor">font-stretch</dfn>
jdaggett@518 2596
jdaggett@518 2597 <tr>
jdaggett@518 2598 <td>Value:
jdaggett@518 2599
jdaggett@545 2600 <td>normal | ultra-condensed | extra-condensed | condensed |
jdaggett@518 2601 semi-condensed | semi-expanded | expanded | extra-expanded |
jdaggett@525 2602 ultra-expanded
jdaggett@890 2603
jdaggett@890 2604 <tr>
jdaggett@890 2605 <td><em>Initial:</em>
jdaggett@890 2606
jdaggett@890 2607 <td>normal
jdaggett@518 2608 </table>
jdaggett@518 2609
jdaggett@573 2610 <p>These descriptors define the characteristics of a font face and are used
jdaggett@573 2611 in the process of matching styles to specific faces. For a font family
jdaggett@8311 2612 defined with several <a
jdaggett@8311 2613 href="#at-font-face-rule"><code>@font-face</code></a> rules, user agents
jdaggett@8311 2614 can either download all faces in the family or use these descriptors to
jdaggett@8311 2615 selectively download font faces that match actual styles used in document.
jdaggett@8311 2616 The values for these descriptors are the same as those for the
jdaggett@8311 2617 corresponding font properties except that relative keywords are not
jdaggett@8311 2618 allowed, ‘<a href="#bolder"><code class=property>bolder</code></a>’
jdaggett@8311 2619 and ‘<a href="#lighter"><code class=property>lighter</code></a>’. If
jdaggett@8311 2620 these descriptors are omitted, initial values are assumed.
jdaggett@890 2621
jdaggett@890 2622 <p>The value for these font face style attributes is used in place of the
jdaggett@890 2623 style implied by the underlying font data. This allows authors to combine
jdaggett@890 2624 faces in flexible combinations, even in situations where the original font
jdaggett@890 2625 data was arranged differently. User agents that implement synthetic
jdaggett@8272 2626 bolding and obliquing must only apply synthetic styling in cases where the
jdaggett@8272 2627 font descriptors imply this is needed, rather than based on the style
jdaggett@890 2628 attributes implied by the font data.
jdaggett@573 2629
jdaggett@1662 2630 <h3 id=unicode-range-desc><span class=secno>4.5 </span>Character range: the
jdaggett@1662 2631 <a href="#descdef-unicode-range">unicode-range</a> descriptor</h3>
jdaggett@518 2632
jdaggett@518 2633 <table class=descdef>
jdaggett@518 2634 <tbody>
jdaggett@518 2635 <tr>
jdaggett@518 2636 <td>Name:
jdaggett@518 2637
jdaggett@1662 2638 <td><dfn id=descdef-unicode-range>unicode-range</dfn>
jdaggett@518 2639
jdaggett@518 2640 <tr>
jdaggett@518 2641 <td>Value:
jdaggett@518 2642
jdaggett@8225 2643 <td><a href="#urange-value"><var>&lt;urange&gt;</var></a> #
jdaggett@890 2644
jdaggett@890 2645 <tr>
jdaggett@890 2646 <td><em>Initial:</em>
jdaggett@890 2647
jdaggett@1148 2648 <td>U+0-10FFFF
jdaggett@518 2649 </table>
jdaggett@518 2650
jdaggett@8213 2651 <p>This descriptor defines the set of Unicode codepoints that may be
jdaggett@8213 2652 supported by the font face for which it is declared. The descriptor value
jdaggett@8225 2653 is a comma-delimited list of Unicode range (<a
jdaggett@8225 2654 href="#urange-value"><var>&lt;urange&gt;</var></a>) values. The union of
jdaggett@8225 2655 these ranges defines the set of codepoints that serves as a hint for user
jdaggett@8225 2656 agents when deciding whether or not to download a font resource for a
jdaggett@8225 2657 given text run.
jdaggett@8225 2658
jdaggett@8225 2659 <p>Each <dfn id=urange-value><var>&lt;urange&gt;</var></dfn> value is a <a
jdaggett@8225 2660 href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><code
jdaggett@8225 2661 title="UNICODE-RANGE token">UNICODE-RANGE</code></a> token made up of a
jdaggett@8225 2662 "U+" or "u+" prefix followed by a codepoint range in one of the three
jdaggett@8241 2663 forms listed below. Ranges that do not fit one of the these forms are
jdaggett@8241 2664 invalid and cause the declaration to be ignored.
jdaggett@8241 2665
jdaggett@8241 2666 <dl>
jdaggett@8241 2667 <dt>single codepoint (e.g. U+416)
jdaggett@8241 2668
jdaggett@8241 2669 <dd>a valid Unicode codepoint, represented as one to six hexadecimal
jdaggett@8241 2670 digits
jdaggett@8241 2671
jdaggett@8246 2672 <dt>interval range (e.g. U+400-4ff)
jdaggett@8241 2673
jdaggett@8241 2674 <dd>represented as two hyphen-separated valid Unicode codepoints
jdaggett@8241 2675 indicating the inclusive start and end codepoints of a range
jdaggett@8241 2676
jdaggett@8246 2677 <dt>wildcard range (e.g. U+4??)
jdaggett@8241 2678
jdaggett@8241 2679 <dd>defined by the set of codepoints implied when trailing ‘<code
jdaggett@8246 2680 class=css>?</code>’ characters signify any hexadeximal digit
jdaggett@8241 2681 </dl>
jdaggett@573 2682
jdaggett@8213 2683 <p>Individual codepoints are written using hexadecimal values that
jdaggett@8213 2684 correspond to <a href="http://www.unicode.org/charts/">Unicode character
jdaggett@8225 2685 codepoints</a>. Valid Unicode codepoint values vary between 0 and 10FFFF
jdaggett@8225 2686 inclusive. Digit values of codepoints are ASCII case-insensitive. For
jdaggett@8360 2687 interval ranges, the start and end codepoints are valid Unicode values and
jdaggett@8360 2688 the end codepoint is greater than or equal to the start codepoint.
jdaggett@8225 2689
jdaggett@8225 2690 <p>Wildcard ranges specified with ‘?’ that lack an initial digit (e.g.
jdaggett@8225 2691 "U+???") are valid and equivalent to a wildcard range with an initial zero
jdaggett@8225 2692 digit (e.g. "U+0???" = "U+0000-0FFF"). Wildcard ranges that extend beyond
jdaggett@8225 2693 the range of valid Unicode codepoints are invalid. Because of this, the
jdaggett@8225 2694 maximum number of trailing ‘<code class=css>?</code>’ wildcard
jdaggett@8272 2695 characters is five, even though the <a
jdaggett@8225 2696 href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><code
jdaggett@8225 2697 title="UNICODE-RANGE token">UNICODE-RANGE</code></a> token accepts six.
jdaggett@8213 2698
jdaggett@8213 2699 <p>Within the comma-delimited list of Unicode ranges in a ‘<a
jdaggett@8213 2700 href="#descdef-unicode-range"><code
jdaggett@8213 2701 class=property>unicode-range</code></a>’ descriptor declaration, ranges
jdaggett@8241 2702 may overlap. The union of these ranges defines the set of codepoints for
jdaggett@8241 2703 which the corresponding font may be used. User agents must not download or
jdaggett@8241 2704 use the font for codepoints outside this set. User agents may normalize
jdaggett@8241 2705 the list of ranges into a list that is different but represents the same
jdaggett@8241 2706 set of codepoints.
jdaggett@8213 2707
jdaggett@8272 2708 <p>The associated font might not contain glyphs for the entire set of
jdaggett@8213 2709 codepoints defined by the ‘<a href="#descdef-unicode-range"><code
jdaggett@8213 2710 class=property>unicode-range</code></a>’ descriptor. When the font is
jdaggett@8391 2711 used, the <dfn id=effective-character-map>effective character map</dfn> is
jdaggett@8225 2712 the intersection of the codepoints defined by ‘<a
jdaggett@8225 2713 href="#descdef-unicode-range"><code
jdaggett@8225 2714 class=property>unicode-range</code></a>’ with the font's <a
jdaggett@8225 2715 href="#character-map"><em>character map</em></a>. This allows authors to
jdaggett@8225 2716 define supported ranges in terms of broad ranges without worrying about
jdaggett@8225 2717 the precise codepoint ranges supported by the underlying font.
jdaggett@8225 2718
jdaggett@8225 2719 <h3 id=composite-fonts><span class=secno>4.6 </span>Using character ranges
jdaggett@8225 2720 to define composite fonts</h3>
jdaggett@8225 2721
jdaggett@8311 2722 <p>Multiple <a href="#at-font-face-rule"><code>@font-face</code></a> rules
jdaggett@8311 2723 with different unicode ranges for the same family and style descriptor
jdaggett@8311 2724 values can be used to create composite fonts that mix the glyphs from
jdaggett@8311 2725 different fonts for different scripts. This can be used to combine fonts
jdaggett@8311 2726 that only contain glyphs for a single script (e.g. Latin, Greek, Cyrillic)
jdaggett@8311 2727 or it can be used by authors as a way of segmenting a font into fonts for
jdaggett@8311 2728 commonly used characters and less frequently used characters. Since the
jdaggett@8311 2729 user agent will only pull down the fonts it needs this helps reduce page
jdaggett@8311 2730 bandwidth.
jdaggett@8311 2731
jdaggett@8311 2732 <p>If the unicode ranges overlap for a set of <a
jdaggett@8311 2733 href="#at-font-face-rule"><code>@font-face</code></a> rules with the same
jdaggett@8311 2734 family and style descriptor values, the rules are ordered in the reverse
jdaggett@8311 2735 order they were defined; the last rule defined is the first to be checked
jdaggett@8311 2736 for a given character.
jdaggett@890 2737
jdaggett@890 2738 <p>Example ranges for specific languages or characters:
jdaggett@518 2739
jdaggett@518 2740 <dl>
jdaggett@529 2741 <dt>unicode-range: U+A5;
jdaggett@529 2742
jdaggett@1149 2743 <dd>a single code point, the yen/yuan symbol
jdaggett@529 2744
jdaggett@1148 2745 <dt>unicode-range: U+0-7F;
jdaggett@1148 2746
jdaggett@1148 2747 <dd>code range for basic ASCII characters
jdaggett@1148 2748
jdaggett@529 2749 <dt>unicode-range: U+590-5ff;
jdaggett@529 2750
jdaggett@529 2751 <dd>code range for Hebrew characters
jdaggett@529 2752
jdaggett@529 2753 <dt>unicode-range: U+A5, U+4E00-9FFF, U+30??, U+FF00-FF9F;
jdaggett@529 2754
jdaggett@529 2755 <dd>code range for Japanese kanji, hiragana and katakana characters plus
jdaggett@529 2756 yen/yuan symbol
jdaggett@518 2757 </dl>
jdaggett@518 2758
jdaggett@529 2759 <div class=example>
jdaggett@531 2760 <p>The BBC provides news services in a wide variety of languages, many
jdaggett@8311 2761 that are not well supported across all platforms. Using an <a
jdaggett@8311 2762 href="#at-font-face-rule"><code>@font-face</code></a> rule, the BBC could
jdaggett@8311 2763 provide a font for any of these languages, as it already does via a
jdaggett@8311 2764 manual font download.</p>
jdaggett@531 2765
jdaggett@531 2766 <pre>
jdaggett@531 2767 @font-face {
jdaggett@531 2768 font-family: BBCBengali;
jdaggett@531 2769 src: url(fonts/BBCBengali.ttf) format("opentype");
jdaggett@531 2770 unicode-range: U+00-FF, U+980-9FF;
jdaggett@531 2771 }
jdaggett@531 2772 </pre>
jdaggett@529 2773 </div>
jdaggett@529 2774
jdaggett@529 2775 <div class=example>
jdaggett@531 2776 <p>Technical documents often require a wide range of symbols. The STIX
jdaggett@531 2777 Fonts project is one project aimed at providing fonts to support a wide
jdaggett@531 2778 range of technical typesetting in a standardized way. The example below
jdaggett@531 2779 shows the use of a font that provides glyphs for many of the mathematical
jdaggett@531 2780 and technical symbol ranges within Unicode:</p>
jdaggett@531 2781
jdaggett@531 2782 <pre>
jdaggett@531 2783 @font-face {
jdaggett@531 2784 font-family: STIXGeneral;
jdaggett@531 2785 src: local(STIXGeneral), url(/stixfonts/STIXGeneral.otf);
jdaggett@531 2786 unicode-range: U+000-49F, U+2000-27FF, U+2900-2BFF, U+1D400-1D7FF;
jdaggett@531 2787 }
jdaggett@531 2788 </pre>
jdaggett@529 2789 </div>
jdaggett@529 2790
jdaggett@529 2791 <div class=example>
jdaggett@529 2792 <p>This example shows how an author can override the glyphs used for Latin
jdaggett@529 2793 characters in a Japanese font with glyphs from a different font. The
jdaggett@529 2794 first rule specifies no range so it defaults to the entire range. The
jdaggett@529 2795 range specified in the second rule overlaps but takes precedence because
jdaggett@529 2796 it is defined later.</p>
jdaggett@529 2797
jdaggett@529 2798 <pre>
jdaggett@529 2799 @font-face {
jdaggett@529 2800 font-family: JapaneseWithGentium;
jdaggett@529 2801 src: local(MSMincho);
jdaggett@529 2802 /* no range specified, defaults to entire range */
jdaggett@529 2803 }
jdaggett@529 2804
jdaggett@529 2805 @font-face {
jdaggett@529 2806 font-family: JapaneseWithGentium;
jdaggett@529 2807 src: url(../fonts/Gentium.ttf);
jdaggett@529 2808 unicode-range: U+0-2FF;
jdaggett@529 2809 }
jdaggett@529 2810 </pre>
jdaggett@529 2811 </div>
jdaggett@1148 2812
jdaggett@1148 2813 <div class=example>
jdaggett@1148 2814 <p>Consider a family constructed to optimize bandwidth by separating out
jdaggett@1148 2815 Latin, Japanese and other characters into different font files:</p>
jdaggett@1148 2816
jdaggett@1148 2817 <pre>
jdaggett@1148 2818 /* fallback font - size: 4.5MB */
jdaggett@1148 2819 @font-face {
jdaggett@1148 2820 font-family: DroidSans;
jdaggett@1148 2821 src: url(DroidSansFallback.ttf);
jdaggett@1148 2822 /* no range specified, defaults to entire range */
jdaggett@1148 2823 }
jdaggett@1148 2824
jdaggett@1148 2825 /* Japanese glyphs - size: 1.2MB */
jdaggett@1148 2826 @font-face {
jdaggett@1148 2827 font-family: DroidSans;
jdaggett@1148 2828 src: url(DroidSansJapanese.ttf);
jdaggett@1148 2829 unicode-range: U+3000-9FFF, U+ff??;
jdaggett@1148 2830 }
jdaggett@1148 2831
jdaggett@8277 2832 /* Latin, Greek, Cyrillic along with some
jdaggett@1148 2833 punctuation and symbols - size: 190KB */
jdaggett@1148 2834 @font-face {
jdaggett@1148 2835 font-family: DroidSans;
jdaggett@1148 2836 src: url(DroidSans.ttf);
jdaggett@1148 2837 unicode-range: U+000-5FF, U+1e00-1fff, U+2000-2300;
jdaggett@1148 2838 }
jdaggett@1148 2839 </pre>
jdaggett@1148 2840
jdaggett@1148 2841 <p>For simple Latin text, only the font for Latin characters is
jdaggett@1148 2842 downloaded:</p>
jdaggett@1148 2843
jdaggett@1148 2844 <pre>
jdaggett@1148 2845 body { font-family: DroidSans; }
jdaggett@1148 2846
jdaggett@1148 2847 &lt;p>This is that&lt;/p>
jdaggett@1148 2848 </pre>
jdaggett@1148 2849
jdaggett@1148 2850 <p>In this case the user agent first checks the unicode-range for the font
jdaggett@1148 2851 containing Latin characters (DroidSans.ttf). Since all the characters
jdaggett@1148 2852 above are in the range U+0-5FF, the user agent downloads the font and
jdaggett@1148 2853 renders the text with that font.</p>
jdaggett@1148 2854
jdaggett@1148 2855 <p>Next, consider text that makes use of an arrow character (⇨):</p>
jdaggett@1148 2856
jdaggett@1148 2857 <pre>
jdaggett@1148 2858 &lt;p>This &amp;#x21e8; that&lt;p>
jdaggett@1148 2859 </pre>
jdaggett@1148 2860
jdaggett@1148 2861 <p>The user agent again first checks the unicode-range of the font
jdaggett@1149 2862 containing Latin characters. Since U+2000-2300 includes the arrow code
jdaggett@1149 2863 point (U+21E8), the user agent downloads the font. For this character
jdaggett@1148 2864 however the Latin font does not have a matching glyph, so the effective
jdaggett@1149 2865 unicode-range used for font matching excludes this code point. Next, the
jdaggett@1148 2866 user agent evaluates the Japanese font. The unicode-range for the
jdaggett@1148 2867 Japanese font, U+3000-9FFF and U+ff??, does not include U+21E8, so the
jdaggett@1662 2868 user agent does not download the Japanese font. Next the fallback font is
jdaggett@8311 2869 considered. The <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2870 rule for the fallback font does not define unicode-range so its value
jdaggett@8311 2871 defaults to the range of all Unicode code points. The fallback font is
jdaggett@8311 2872 downloaded and used to render the arrow character.</p>
jdaggett@1148 2873 </div>
jdaggett@890 2874
jdaggett@8225 2875 <h3 id=font-rend-desc><span class=secno>4.7 </span>Font features: the <a
jdaggett@1662 2876 href="#descdef-font-variant">font-variant</a> and <a
jdaggett@1662 2877 href="#descdef-font-feature-settings">font-feature-settings</a>
jdaggett@1662 2878 descriptors</h3>
jdaggett@1662 2879
jdaggett@1662 2880 <table class=descdef>
jdaggett@1662 2881 <tbody>
jdaggett@1662 2882 <tr>
jdaggett@1662 2883 <td>Name:
jdaggett@1662 2884
jdaggett@8278 2885 <td><dfn id=descdef-font-variant
jdaggett@8278 2886 title="font-variant!!descriptor">font-variant</dfn>
jdaggett@1662 2887
jdaggett@1662 2888 <tr>
jdaggett@1662 2889 <td>Value:
jdaggett@1662 2890
jdaggett@8278 2891 <td><a href="#font-variant-normal-value"
jdaggett@8278 2892 title="normal!!font-variant">normal</a> | <a
jdaggett@8278 2893 href="#font-variant-none-value" title="none!!font-variant">none</a> | [
jdaggett@8278 2894 <a href="#common-lig-values"><var>&lt;common-lig-values&gt;</var></a>
jdaggett@8278 2895 || <a
jdaggett@8225 2896 href="#discretionary-lig-values"><var>&lt;discretionary-lig-values&gt;</var></a>
jdaggett@8225 2897 || <a
jdaggett@8225 2898 href="#historical-lig-values"><var>&lt;historical-lig-values&gt;</var></a>
jdaggett@8225 2899 || <a
jdaggett@8225 2900 href="#contextual-alt-values"><var>&lt;contextual-alt-values&gt;</var></a>
jdaggett@8225 2901 || <a href="#stylistic"><var
jdaggett@8225 2902 title=stylistic>stylistic(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 2903 href="#historical-forms"><var>historical-forms</var></a> || <a
jdaggett@8225 2904 href="#styleset"><var
jdaggett@8225 2905 title=styleset>styleset(&lt;feature-value-name&gt; #)</var></a> || <a
jdaggett@8225 2906 href="#character-variant"><var
jdaggett@8225 2907 title=character-variant>character-variant(&lt;feature-value-name&gt;
jdaggett@8225 2908 #)</var></a> || <a href="#swash"><var
jdaggett@8225 2909 title=swash>swash(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 2910 href="#ornaments"><var
jdaggett@8225 2911 title=ornaments>ornaments(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 2912 href="#annotation"><var
jdaggett@8225 2913 title=annotation>annotation(&lt;feature-value-name&gt;)</var></a> || [
jdaggett@8225 2914 <a href="#small-caps"><i>small-caps</i></a> | <a
jdaggett@8225 2915 href="#all-small-caps"><i>all-small-caps</i></a> | <a
jdaggett@8225 2916 href="#petite-caps"><i>petite-caps</i></a> | <a
jdaggett@8225 2917 href="#all-petite-caps"><i>all-petite-caps</i></a> | <a
jdaggett@8225 2918 href="#unicase"><i>unicase</i></a> | <a
jdaggett@8225 2919 href="#titling-caps"><i>titling-caps</i></a> ] || <a
jdaggett@8225 2920 href="#numeric-figure-values"><var>&lt;numeric-figure-values&gt;</var></a>
jdaggett@8225 2921 || <a
jdaggett@8225 2922 href="#numeric-spacing-values"><var>&lt;numeric-spacing-values&gt;</var></a>
jdaggett@8225 2923 || <a
jdaggett@8225 2924 href="#numeric-fraction-values"><var>&lt;numeric-fraction-values&gt;</var></a>
jdaggett@8225 2925 || <a href="#ordinal"><i>ordinal</i></a> || <a
jdaggett@8225 2926 href="#slashed-zero"><i>slashed-zero</i></a> || <a
jdaggett@8225 2927 href="#east-asian-variant-values"><var>&lt;east-asian-variant-values&gt;</var></a>
jdaggett@8225 2928 || <a
jdaggett@8225 2929 href="#east-asian-width-values"><var>&lt;east-asian-width-values&gt;</var></a>
jdaggett@8225 2930 || <a href="#ruby"><i>ruby</i></a> ]
jdaggett@1662 2931
jdaggett@1662 2932 <tr>
jdaggett@1662 2933 <td><em>Initial:</em>
jdaggett@1662 2934
jdaggett@1662 2935 <td>normal
jdaggett@1662 2936 </table>
jdaggett@1662 2937
jdaggett@1662 2938 <table class=descdef>
jdaggett@1662 2939 <tbody>
jdaggett@1662 2940 <tr>
jdaggett@1662 2941 <td>Name:
jdaggett@1662 2942
jdaggett@8278 2943 <td><dfn id=descdef-font-feature-settings
jdaggett@8278 2944 title="font-feature-settings!!descriptor">font-feature-settings</dfn>
jdaggett@1662 2945
jdaggett@1662 2946 <tr>
jdaggett@1662 2947 <td>Value:
jdaggett@1662 2948
jdaggett@8278 2949 <td><a href="#font-feature-settings-normal-value"
jdaggett@8278 2950 title="normal!!font-feature-settings">normal</a> | <a
jdaggett@8225 2951 href="#feature-tag-value"><var>&lt;feature-tag-value&gt;</var></a> #
jdaggett@1662 2952
jdaggett@1662 2953 <tr>
jdaggett@1662 2954 <td><em>Initial:</em>
jdaggett@1662 2955
jdaggett@1662 2956 <td>normal
jdaggett@1662 2957 </table>
jdaggett@1662 2958
jdaggett@8213 2959 <p>These descriptors define initial settings that apply when the font
jdaggett@8311 2960 defined by an <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 2961 rule is rendered. They do not affect font selection. Values are identical
jdaggett@8311 2962 to those defined for the corresponding <a href="#propdef-font-variant"
jdaggett@8278 2963 title="font-variant!!property">‘<code
jdaggett@8279 2964 class=property>font-variant</code>’</a> and <a
jdaggett@8279 2965 href="#propdef-font-feature-settings"
jdaggett@8279 2966 title="font-feature-settings!!property">‘<code
jdaggett@8279 2967 class=property>font-feature-settings</code>’</a> properties defined
jdaggett@8279 2968 below except that the value ‘<code class=property>inherit</code>’ is
jdaggett@8279 2969 omitted. When multiple font feature descriptors or properties are used,
jdaggett@8279 2970 the cumulative effect on text rendering is detailed in the section <a
jdaggett@8031 2971 href="#font-feature-resolution">Font Feature Resolution</a> below. In
jdaggett@8278 2972 cases where specific values define synthesized fallback for certain <a
jdaggett@8278 2973 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8278 2974 class=property>font-variant</code>’</a> subproperties, the same
jdaggett@8031 2975 synthesized fallback applies when used within those values are used with
jdaggett@8278 2976 the <a href="#descdef-font-style" title="font-style!!descriptor">‘<code
jdaggett@8031 2977 class=property>font-variant</code>’</a> descriptor.
jdaggett@1662 2978
jdaggett@8225 2979 <h3 id=font-face-loading><span class=secno>4.8 </span>Font loading
jdaggett@2563 2980 guidelines</h3>
jdaggett@2563 2981
jdaggett@8311 2982 <p>The <a href="#at-font-face-rule"><code>@font-face</code></a> rule is
jdaggett@8311 2983 designed to allow lazy loading of font resources that are only downloaded
jdaggett@8311 2984 when used within a document. A stylesheet can include <a
jdaggett@8311 2985 href="#at-font-face-rule"><code>@font-face</code></a> rules for a library
jdaggett@8311 2986 of fonts of which only a select set are used; user agents must only
jdaggett@8311 2987 download those fonts that are referred to within the style rules
jdaggett@8311 2988 applicable to a given page. User agents that download all fonts defined in
jdaggett@8311 2989 <a href="#at-font-face-rule"><code>@font-face</code></a> rules without
jdaggett@8311 2990 considering whether those fonts are in fact used within a page are
jdaggett@8311 2991 considered non-conformant. In cases where a font might be downloaded in
jdaggett@8360 2992 character fallback cases, user agents may download a font if it's
jdaggett@8360 2993 contained within the computed value of <a href="#propdef-font-family"
jdaggett@8360 2994 title="font-family!!property">‘<code
jdaggett@8360 2995 class=property>font-family</code>’</a> for a given text run.
jdaggett@2563 2996
jdaggett@2563 2997 <pre>
jdaggett@2563 2998 @font-face {
jdaggett@2563 2999 font-family: GeometricModern;
jdaggett@2563 3000 src: url(font.ttf);
jdaggett@2563 3001 }
jdaggett@2563 3002
jdaggett@2563 3003 p {
jdaggett@2563 3004 /* font will be downloaded for pages with p elements */
jdaggett@2563 3005 font-family: GeometricModern, sans-serif;
jdaggett@2563 3006 }
jdaggett@2563 3007
jdaggett@2563 3008 h2 {
jdaggett@2563 3009 /* font may be downloaded for pages with h2 elements, even if Futura is available locally */
jdaggett@2563 3010 font-family: Futura, GeometricModern, sans-serif;
jdaggett@2563 3011 }
jdaggett@2563 3012 </pre>
jdaggett@2563 3013
jdaggett@2563 3014 <p>In cases where textual content is loaded before downloadable fonts are
jdaggett@2563 3015 available, user agents may render text as it would be rendered if
jdaggett@2563 3016 downloadable font resources are not available or they may render text
jdaggett@2563 3017 transparently with fallback fonts to avoid a flash of text using a
jdaggett@2563 3018 fallback font. In cases where the font download fails user agents must
jdaggett@2563 3019 display text, simply leaving transparent text is considered non-conformant
jdaggett@2563 3020 behavior. Authors are advised to use fallback fonts in their font lists
jdaggett@8431 3021 that closely match the metrics of the downloadable fonts to avoid large
jdaggett@8431 3022 page reflows where possible.
jdaggett@2563 3023
jdaggett@8225 3024 <h3 id=same-origin-restriction><span class=secno>4.9 </span>Same-origin
jdaggett@2737 3025 restriction for fonts</h3>
jdaggett@2737 3026
jdaggett@8225 3027 <h4 id=default-same-origin-restriction><span class=secno>4.9.1
jdaggett@2740 3028 </span>Default same-origin restriction</h4>
jdaggett@7253 3029 <!-- TPAC 2011 Resolution to require same-origin restriction for loading fonts:
jdaggett@7253 3030 http://lists.w3.org/Archives/Public/www-style/2011Nov/0711.html
jdaggett@7253 3031 http://www.w3.org/2011/10/31-webapps-minutes.html#item02
jdaggett@7253 3032 -->
jdaggett@2740 3033
jdaggett@2737 3034 <p>User agents must implement a same-origin restriction when loading fonts
jdaggett@8311 3035 via the <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 3036 mechanism. This restriction limits the loading of fonts for a given
jdaggett@8311 3037 document to fonts loaded from the same origin. Fonts can only be loaded
jdaggett@8311 3038 via the same host, port, and method combination as the containing
jdaggett@8311 3039 document, using the <a
jdaggett@7179 3040 href="http://www.w3.org/TR/html5/browsers.html#origin">origin matching
jdaggett@2737 3041 algorithm</a> described in the <a href="#HTML5"
jdaggett@2737 3042 rel=biblioentry>[HTML5]<!--{{!HTML5}}--></a> specification. The origin of
jdaggett@8311 3043 the stylesheet containing <a
jdaggett@8311 3044 href="#at-font-face-rule"><code>@font-face</code></a> rules is not used
jdaggett@8311 3045 when deciding whether a font is same origin or not, only the origin of the
jdaggett@7096 3046 containing document is used. The restriction applies to all font types.
jdaggett@2737 3047
jdaggett@2737 3048 <p>Given a document located at http://example.com/page.html, fonts defined
jdaggett@4624 3049 with ‘<a href="#descdef-src"><code class=property>src</code></a>’
jdaggett@2737 3050 definitions considered cross origin must not be loaded:
jdaggett@2737 3051
jdaggett@2737 3052 <pre>
jdaggett@8640 3053 /* same origin (i.e. domain, scheme, port match document) */
jdaggett@8277 3054 src: url(fonts/simple.ttf);
jdaggett@8277 3055 src: url(//fonts/simple.ttf);
jdaggett@2737 3056
jdaggett@8640 3057 /* cross origin, different scheme */
jdaggett@8277 3058 src: url(https://example.com/fonts/simple.ttf);
jdaggett@2737 3059
jdaggett@2737 3060 /* cross origin, different domain */
jdaggett@8277 3061 src: url(http://another.example.com/fonts/simple.ttf);
jdaggett@2737 3062 </pre>
jdaggett@2737 3063
jdaggett@8225 3064 <h4 id=allowing-cross-origin-font-loading><span class=secno>4.9.2
jdaggett@2740 3065 </span>Allowing cross-origin font loading</h4>
jdaggett@2740 3066
jdaggett@2737 3067 <p>User agents must also implement the ability to relax this restriction
jdaggett@2737 3068 using cross-site origin controls <a href="#CORS"
jdaggett@7253 3069 rel=biblioentry>[CORS]<!--{{!CORS}}--></a> for fonts loaded via HTTP.
jdaggett@7253 3070 Sites can explicitly allow cross-site downloading of font data using the
jdaggett@8640 3071 <code>Access-Control-Allow-Origin</code> HTTP header. For other schemes,
jdaggett@7253 3072 no explicit relaxation mechanism is defined or required.
jdaggett@7253 3073
jdaggett@8640 3074 <p>For font loads, user agents must use the <a
jdaggett@8640 3075 href="http://www.w3.org/TR/html5/infrastructure.html#cors-enabled-fetch">potentially
jdaggett@8640 3076 CORS-enabled fetch</a> method defined by the <a href="#HTML5"
jdaggett@8640 3077 rel=biblioentry>[HTML5]<!--{{!HTML5}}--></a> specification for URL's
jdaggett@8640 3078 defined within @font-face rules. When fetching, user agents must use
jdaggett@8640 3079 "Anonymous" mode, set the referrer source to the stylesheet's URL and set
jdaggett@8640 3080 the origin to the URL of the containing document.
jdaggett@2737 3081
jdaggett@6699 3082 <h2 id=font-matching-algorithm><span class=secno>5 </span>Font Matching
jdaggett@6699 3083 Algorithm</h2>
jdaggett@484 3084
jdaggett@2457 3085 <p>The algorithm below describes how fonts are associated with individual
jdaggett@2457 3086 runs of text. For each character in the run a font family is chosen and a
jdaggett@2457 3087 particular font face is selected containing a glyph for that character.
jdaggett@2457 3088
jdaggett@7309 3089 <h3 id=font-family-casing><span class=secno>5.1 </span>Case sensitivity of
jdaggett@7309 3090 font family names</h3>
jdaggett@7309 3091
jdaggett@7309 3092 <p>As part of the font matching algorithm outlined below, user agents must
jdaggett@7309 3093 match font family names used in style rules with actual font family names
jdaggett@8391 3094 contained in fonts available in a given environment or with font family
jdaggett@8391 3095 names defined in <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8391 3096 rules. User agents must match these names case insensitively, using the
jdaggett@8391 3097 "Default Caseless Matching" algorithm outlined in the Unicode
jdaggett@8391 3098 specification <a href="#UNICODE6"
jdaggett@8391 3099 rel=biblioentry>[UNICODE6]<!--{{!UNICODE6}}--></a>. This algorithm is
jdaggett@8391 3100 detailed in section 3.13 entitled "Default Case Algorithms". Specifically,
jdaggett@8391 3101 the algorithm must be applied without normalizing the strings involved and
jdaggett@8391 3102 without applying any language-specific tailorings. The case folding method
jdaggett@8391 3103 specified by this algorithm uses the case mappings with status field
jdaggett@8391 3104 ‘<code class=property>C</code>’ or ‘<code class=property>F</code>’
jdaggett@8391 3105 in the CaseFolding.txt file of the Unicode Character Database.
jdaggett@7355 3106
jdaggett@7355 3107 <p class=note> For authors this means that font family names are matched
jdaggett@8272 3108 case insensitively, whether those names exist in a platform font or in the
jdaggett@8311 3109 <a href="#at-font-face-rule"><code>@font-face</code></a> rules contained
jdaggett@8311 3110 in a stylesheet. Authors should take care to ensure that names use a
jdaggett@8311 3111 character sequence consistent with the actual font family name,
jdaggett@8311 3112 particularly when using combining characters such as diacritical marks.
jdaggett@8311 3113 For example, a family name that contains an uppercase A (U+0041) followed
jdaggett@8311 3114 by a combining ring (U+030A) will <strong>not</strong> match a name that
jdaggett@8311 3115 looks identical but which uses the precomposed lowercase a-ring character
jdaggett@8311 3116 (U+00E5) instead of the combining sequence.
jdaggett@7309 3117
jdaggett@8391 3118 <p class=note> Implementors should take care to verify that a given
jdaggett@8391 3119 caseless string comparison implementation uses this precise algorithm and
jdaggett@8391 3120 not assume that a given platform string matching routine follows it, as
jdaggett@8391 3121 many of these have locale-specific behavior or use some level of string
jdaggett@8391 3122 normalization.
jdaggett@8391 3123
jdaggett@7309 3124 <h3 id=font-style-matching><span class=secno>5.2 </span>Matching font
jdaggett@2457 3125 styles</h3>
jdaggett@2457 3126
jdaggett@8391 3127 <p>The procedure for choosing a font for a given character in a run of text
jdaggett@8391 3128 consists of iterating over the font families named by the <a
jdaggett@8391 3129 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8391 3130 class=property>font-family</code>’</a> property, selecting a font face
jdaggett@531 3131 with the appropriate style based on other font properties and then
jdaggett@8391 3132 determining whether a glyph exists for the given character. This is done
jdaggett@7311 3133 using the <dfn id=character-map>character map</dfn> of the font, data
jdaggett@8397 3134 which maps characters to the default glyph for that character. A font is
jdaggett@8397 3135 considered to <dfn id=support>support</dfn> a given character if (1) the
jdaggett@8397 3136 character is contained in the font's <a
jdaggett@8397 3137 href="#character-map"><em>character map</em></a> and (2) if required by
jdaggett@8397 3138 the containing script, shaping information is available for that
jdaggett@8397 3139 character.
jdaggett@8397 3140
jdaggett@8397 3141 <p>Some legacy fonts may include a given character in the <a
jdaggett@8397 3142 href="#character-map"><em>character map</em></a> but lack the shaping
jdaggett@8397 3143 information (e.g. <a
jdaggett@8397 3144 href="http://www.microsoft.com/typography/otspec/ttochap1.htm">OpenType
jdaggett@8397 3145 layout tables</a> or <a
jdaggett@8397 3146 href="http://scripts.sil.org/cms/scripts/page.php?site_id=projects&amp;item_id=graphite_techAbout">Graphite
jdaggett@8397 3147 tables</a>) necessary for correctly rendering text runs containing that
jdaggett@8397 3148 character.
jdaggett@8397 3149
jdaggett@8397 3150 <p>Codepoint sequences consisting of a base character followed by a
jdaggett@8397 3151 sequence of combining characters are treated slightly differently, see the
jdaggett@8397 3152 section on <a href="#cluster-matching">cluster matching</a> below.
jdaggett@531 3153
jdaggett@7232 3154 <p>For this procedure, the <dfn id=default-face>default face</dfn> for a
jdaggett@7232 3155 given font family is defined to be the face that would be selected if all
jdaggett@7232 3156 font style properties were set to their initial value.
jdaggett@7232 3157
jdaggett@531 3158 <ol id=fontmatchingalg>
jdaggett@2457 3159 <li>Using the computed font property values for a given element, the user
jdaggett@8391 3160 agent starts with the first family name specified by the <a
jdaggett@8391 3161 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8278 3162 class=property>font-family</code>’</a> property.
jdaggett@2457 3163
jdaggett@8391 3164 <li>If the family name is a generic family keyword, the user agent looks
jdaggett@8391 3165 up the appropriate font family name to be used. User agents may choose
jdaggett@8391 3166 the generic font family to use based on the language of the containing
jdaggett@8391 3167 element or the Unicode range of the character.
jdaggett@2457 3168
jdaggett@2457 3169 <li>For other family names, the user agent attempts to find the family
jdaggett@8311 3170 name among fonts defined via <a
jdaggett@8311 3171 href="#at-font-face-rule"><code>@font-face</code></a> rules and then
jdaggett@8391 3172 among available system fonts, matching names with a <a
jdaggett@8391 3173 href="#font-family-casing">case-insensitive comparison</a> as outlined in
jdaggett@8391 3174 the section above. On systems containing fonts with multiple localized
jdaggett@8391 3175 font family names, user agents must match any of these names independent
jdaggett@8391 3176 of the underlying system locale or platform API used. If the font
jdaggett@8391 3177 resources defined for a given face in an <a
jdaggett@8311 3178 href="#at-font-face-rule"><code>@font-face</code></a> rule are either not
jdaggett@8311 3179 available or contain invalid font data, then the face should be treated
jdaggett@8311 3180 as not present in the family. If no faces are present for a family
jdaggett@8311 3181 defined via <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 3182 rules, the family should be treated as missing; matching a platform font
jdaggett@8311 3183 with the same name must not occur in this case.
jdaggett@2457 3184
jdaggett@2457 3185 <li>If a font family match occurs, the user agent assembles the set of
jdaggett@6701 3186 font faces in that family and then narrows the set to a single face using
jdaggett@8391 3187 other font properties in the order given below. A group of faces defined
jdaggett@8391 3188 via <a href="#at-font-face-rule"><code>@font-face</code></a> rules with
jdaggett@8391 3189 identical font descriptor values but differing ‘<a
jdaggett@8391 3190 href="#descdef-unicode-range"><code
jdaggett@8391 3191 class=property>unicode-range</code></a>’ values are considered to be a
jdaggett@8391 3192 single <dfn id=composite-face>composite face</dfn> for this step:
jdaggett@2457 3193 <ol id=fontstylematchingalg>
jdaggett@8278 3194 <li><a href="#propdef-font-stretch"
jdaggett@8278 3195 title="font-stretch!!property">‘<code
jdaggett@8278 3196 class=property>font-stretch</code>’</a> is tried first. If the
jdaggett@8278 3197 matching set contains faces with width values matching the <a
jdaggett@8278 3198 href="#propdef-font-stretch" title="font-stretch!!property">‘<code
jdaggett@8278 3199 class=property>font-stretch</code>’</a> value, faces with other width
jdaggett@4624 3200 values are removed from the matching set. If there is no face that
jdaggett@4624 3201 exactly matches the width value the nearest width is used instead. If
jdaggett@8278 3202 the value of <a href="#propdef-font-stretch"
jdaggett@8278 3203 title="font-stretch!!property">‘<code
jdaggett@8368 3204 class=property>font-stretch</code>’</a> is <a
jdaggett@8368 3205 href="#font-stretch-normal-value" title="normal!!font-stretch">‘<code
jdaggett@8368 3206 class=property>normal</code>’</a> or one of the condensed values,
jdaggett@8278 3207 narrower width values are checked first, then wider values. If the
jdaggett@8278 3208 value of <a href="#propdef-font-stretch"
jdaggett@8278 3209 title="font-stretch!!property">‘<code
jdaggett@8278 3210 class=property>font-stretch</code>’</a> is one of the expanded
jdaggett@4624 3211 values, wider values are checked first, followed by narrower values.
jdaggett@4624 3212 Once the closest matching width has been determined by this process,
jdaggett@4624 3213 faces with other widths are removed from the matching set.
jdaggett@4624 3214
jdaggett@8278 3215 <li><a href="#propdef-font-style" title="font-style!!property">‘<code
jdaggett@8278 3216 class=property>font-style</code>’</a> is tried next. If the value of
jdaggett@8278 3217 <a href="#propdef-font-style" title="font-style!!property">‘<code
jdaggett@8278 3218 class=property>font-style</code>’</a> is ‘<a href="#italic"><code
jdaggett@8278 3219 class=property>italic</code></a>’, italic faces are checked first,
jdaggett@8278 3220 then oblique, then normal faces. If the value is ‘<a
jdaggett@8278 3221 href="#oblique"><code class=property>oblique</code></a>’, oblique
jdaggett@8278 3222 faces are checked first, then italic faces and then normal faces. If
jdaggett@8368 3223 the value is <a href="#font-style-normal-value"
jdaggett@8368 3224 title="normal!!font-style">‘<code
jdaggett@8368 3225 class=property>normal</code>’</a>, normal faces are checked first,
jdaggett@8279 3226 then oblique faces, then italic faces. Faces with other style values
jdaggett@8279 3227 are excluded from the matching set. User agents are permitted to
jdaggett@8279 3228 distinguish between italic and oblique faces within platform font
jdaggett@8391 3229 families but this is not required, so all italic or oblique faces may
jdaggett@8391 3230 be treated as italic faces. However, within font families defined via
jdaggett@8391 3231 <a href="#at-font-face-rule"><code>@font-face</code></a> rules, italic
jdaggett@8391 3232 and oblique faces must be distinguished using the value of the <a
jdaggett@8311 3233 href="#descdef-font-style" title="font-style!!descriptor">‘<code
jdaggett@8391 3234 class=property>font-style</code>’</a> descriptor. For families that
jdaggett@8391 3235 lack any italic or oblique faces, users agents may create artificial
jdaggett@8391 3236 oblique faces, if this is permitted by the value of the ‘<a
jdaggett@8391 3237 href="#propdef-font-synthesis"><code
jdaggett@8391 3238 class=property>font-synthesis</code></a>’ property.
jdaggett@8278 3239
jdaggett@8278 3240 <li><a href="#propdef-font-weight"
jdaggett@8278 3241 title="font-weight!!property">‘<code
jdaggett@8391 3242 class=property>font-weight</code>’</a> is matched next, so it will
jdaggett@8278 3243 always reduce the matching set to a single font face. If bolder/lighter
jdaggett@8278 3244 relative weights are used, the effective weight is calculated based on
jdaggett@8278 3245 the inherited weight value, as described in the definition of the <a
jdaggett@8278 3246 href="#propdef-font-weight" title="font-weight!!property">‘<code
jdaggett@8278 3247 class=property>font-weight</code>’</a> property. Given the desired
jdaggett@4624 3248 weight and the weights of faces in the matching set after the steps
jdaggett@4624 3249 above, if the desired weight is available that face matches. Otherwise,
jdaggett@4624 3250 a weight is chosen using the rules below:
jdaggett@531 3251 <ul>
jdaggett@531 3252 <li>If the desired weight is less than 400, weights below the desired
jdaggett@531 3253 weight are checked in descending order followed by weights above the
jdaggett@531 3254 desired weight in ascending order until a match is found.
jdaggett@531 3255
jdaggett@531 3256 <li>If the desired weight is greater than 500, weights above the
jdaggett@531 3257 desired weight are checked in ascending order followed by weights
jdaggett@531 3258 below the desired weight in descending order until a match is found.
jdaggett@531 3259
jdaggett@531 3260 <li>If the desired weight is 400, 500 is checked first and then the
jdaggett@531 3261 rule for desired weights less than 400 is used.
jdaggett@531 3262
jdaggett@531 3263 <li>If the desired weight is 500, 400 is checked first and then the
jdaggett@532 3264 rule for desired weights less than 400 is used.
jdaggett@531 3265 </ul>
jdaggett@531 3266
jdaggett@4624 3267 <li><span class=property>‘<a href="#propdef-font-size"><code
jdaggett@4624 3268 class=property>font-size</code></a>’</span> must be matched within a
jdaggett@4624 3269 UA-dependent margin of tolerance. (Typically, sizes for scalable fonts
jdaggett@4624 3270 are rounded to the nearest whole pixel, while the tolerance for
jdaggett@4624 3271 bitmapped fonts could be as large as 20%.) Further computations, e.g.,
jdaggett@4624 3272 by ‘<code class=property>em</code>’ values in other properties, are
jdaggett@4624 3273 based on the <span class=property>‘<a href="#propdef-font-size"><code
jdaggett@4624 3274 class=property>font-size</code></a>’</span> value that is used, not
jdaggett@4624 3275 the one that is specified.
jdaggett@531 3276 </ol>
jdaggett@531 3277
jdaggett@7232 3278 <li>
jdaggett@8391 3279 <p>If the matched face is defined via <a
jdaggett@8391 3280 href="#at-font-face-rule"><code>@font-face</code></a> rules, user agents
jdaggett@8391 3281 must use the procedure below to select a single font:
jdaggett@8391 3282
jdaggett@8391 3283 <ol>
jdaggett@8391 3284 <li>If the font resource has not been loaded and the range of characters
jdaggett@8391 3285 defined by the ‘<a href="#descdef-unicode-range"><code
jdaggett@8391 3286 class=property>unicode-range</code></a>’ descriptor value includes
jdaggett@8391 3287 the character in question, load the font.
jdaggett@8391 3288
jdaggett@8391 3289 <li>After downloading, if the <a
jdaggett@8391 3290 href="#effective-character-map"><em>effective character map</em></a>
jdaggett@8391 3291 supports the character in question, select that font.
jdaggett@8391 3292 </ol>
jdaggett@8391 3293
jdaggett@8391 3294 <p>When the matched face is a <a href="#composite-face"><em>composite
jdaggett@8391 3295 face</em></a>, user agents must use the procedure above on each of the
jdaggett@8391 3296 faces in the <a href="#composite-face"><em>composite face</em></a> in
jdaggett@8391 3297 reverse order of <a
jdaggett@8391 3298 href="#at-font-face-rule"><code>@font-face</code></a> rule definition.</p>
jdaggett@8391 3299
jdaggett@8391 3300 <p>While the download occurs, user agents may either wait until the font
jdaggett@8391 3301 is downloaded or render once with substituted font metrics and render
jdaggett@8391 3302 again once the font is downloaded.</p>
jdaggett@8391 3303
jdaggett@8391 3304 <li>
jdaggett@7232 3305 <p>If no matching face exists or the matched face does not contain a
jdaggett@7232 3306 glyph for the character to be rendered, the next family name is selected
jdaggett@8391 3307 and the previous three steps repeated. Glyphs from other faces in the
jdaggett@7232 3308 family are not considered. The only exception is that user agents may
jdaggett@8391 3309 optionally substitute a synthetically obliqued version of the <a
jdaggett@7232 3310 href="#default-face"><em>default face</em></a> if that face supports a
jdaggett@8391 3311 given glyph and synthesis of these faces is permitted by the value of
jdaggett@8391 3312 the ‘<a href="#propdef-font-synthesis"><code
jdaggett@8391 3313 class=property>font-synthesis</code></a>’ property. For example, a
jdaggett@8391 3314 synthetic italic version of the regular face may be used if the italic
jdaggett@8391 3315 face doesn't support glyphs for Arabic.</p>
jdaggett@7242 3316 <!-- resolution on the above: http://lists.w3.org/Archives/Public/www-style/2012Nov/0292.html -->
jdaggett@7242 3317
jdaggett@531 3318
jdaggett@531 3319 <li>If there are no more font families to be evaluated and no matching
jdaggett@8363 3320 face has been found, then the user agent performs a <dfn
jdaggett@8363 3321 id=system-font-fallback>system font fallback</dfn> procedure to find the
jdaggett@8363 3322 best match for the character to be rendered. The result of this procedure
jdaggett@8363 3323 may vary across user agents.
jdaggett@531 3324
jdaggett@531 3325 <li>If a particular character cannot be displayed using any font, the user
jdaggett@531 3326 agent should indicate by some means that a character is not being
jdaggett@2457 3327 displayed, displaying either a symbolic representation of the missing
jdaggett@2457 3328 glyph (e.g. using a <a
jdaggett@2457 3329 href="http://en.wikipedia.org/wiki/Last_resort_font">Last Resort
jdaggett@2457 3330 Font</a>) or using the missing character glyph from a default font.
jdaggett@512 3331 </ol>
jdaggett@2457 3332
jdaggett@8430 3333 <p>Optimizations of this process are allowed provided that an
jdaggett@8430 3334 implementation behaves as if the algorithm had been followed exactly.
jdaggett@8430 3335 Matching occurs in a well-defined order to insure that the results are as
jdaggett@8430 3336 consistent as possible across user agents, given an identical set of
jdaggett@8430 3337 available fonts and rendering technology.
jdaggett@8430 3338
jdaggett@8431 3339 <p>The <dfn id=first-available-font>first available font</dfn>, used in the
jdaggett@8431 3340 definition of <a
jdaggett@8431 3341 href="http://www.w3.org/TR/css3-values/#font-relative-lengths"><em>font-relative
jdaggett@8431 3342 lengths</em></a> such as ‘<code class=property>ex</code>’ and ‘<code
jdaggett@8431 3343 class=property>ch</code>’, is defined to be the first available font
jdaggett@8431 3344 that would match any character given font families in the ‘<code
jdaggett@8431 3345 class=property>font-family</code>’ list (or a user agent's default font
jdaggett@8431 3346 if none are available).
jdaggett@8431 3347
jdaggett@7309 3348 <h3 id=cluster-matching><span class=secno>5.3 </span>Cluster matching</h3>
jdaggett@6701 3349
jdaggett@8397 3350 <p>When text contains characters such as combining marks, ideally the base
jdaggett@8397 3351 character should be rendered using the same font as the mark, this assures
jdaggett@8397 3352 proper placement of the mark. For this reason, the font matching algorithm
jdaggett@8397 3353 for clusters is more specialized than the general case of matching a
jdaggett@8397 3354 single character by itself. For sequences containing variation selectors,
jdaggett@8397 3355 which indicate the precise glyph to be used for a given character, user
jdaggett@8397 3356 agents always attempt <a href="#system-font-fallback"><em>system font
jdaggett@8397 3357 fallback</em></a> to find the appropriate glyph before using the default
jdaggett@8397 3358 glyph of the base character.
jdaggett@8397 3359
jdaggett@8397 3360 <p>A sequence of codepoints containing combining mark or other modifiers is
jdaggett@8397 3361 termed a grapheme cluster (see <a href="#CSS3TEXT"
jdaggett@6701 3362 rel=biblioentry>[CSS3TEXT]<!--{{CSS3TEXT}}--></a> for a more complete
jdaggett@6701 3363 description). For a given cluster containing a base character, <em>b</em>
jdaggett@6701 3364 and a sequence of combining characters <em>c1, c2…</em>, the entire
jdaggett@6701 3365 cluster is matched using these steps:
jdaggett@6701 3366
jdaggett@6701 3367 <ol>
jdaggett@6701 3368 <li>For each family in the font list, a face is chosen using the style
jdaggett@6701 3369 selection rules defined in the previous section.
jdaggett@6701 3370 <ol>
jdaggett@7020 3371 <li>If all characters in the sequence <em>b + c1 + c2 …</em> are
jdaggett@7021 3372 completely supported by the font, select this font for the sequence.
jdaggett@6701 3373
jdaggett@6701 3374 <li>If a sequence of multiple codepoints is canonically equivalent to a
jdaggett@8397 3375 single character and the font <a href="#support"><em
jdaggett@8397 3376 title=support>supports</em></a> that character, select this font for
jdaggett@8397 3377 the sequence.
jdaggett@6701 3378 </ol>
jdaggett@6701 3379
jdaggett@6701 3380 <li>If no font was found in the font list in step 1:
jdaggett@6701 3381 <ol>
jdaggett@6701 3382 <li>If <em>c1</em> is a variation selector, system fallback must be used
jdaggett@8397 3383 to find a font that <a href="#support"><em
jdaggett@8397 3384 title=support>supports</em></a> the full sequence of <em>b + c1</em>.
jdaggett@8397 3385 If no font on the system <a href="#support"><em
jdaggett@8397 3386 title=support>supports</em></a> the full sequence, match the single
jdaggett@6701 3387 character <em>b</em> using the normal procedure for matching single
jdaggett@6701 3388 characters and ignore the variation selector. Note: a sequence with
jdaggett@8397 3389 more than one variation selector must be treated as an encoding error
jdaggett@8397 3390 and the trailing selectors must be ignored. <a href="#UNICODE6"
jdaggett@8397 3391 rel=biblioentry>[UNICODE6]<!--{{!UNICODE6}}--></a>
jdaggett@6701 3392
jdaggett@6701 3393 <li>Otherwise, the user agent may optionally use system font fallback to
jdaggett@8397 3394 match a font that <a href="#support"><em
jdaggett@8397 3395 title=support>supports</em></a> the entire cluster.
jdaggett@6701 3396 </ol>
jdaggett@6701 3397
jdaggett@6701 3398 <li>If no font is found in step 2, use the matching sequence from step 1
jdaggett@8397 3399 to determine the longest sequence that is completely <a
jdaggett@8397 3400 href="#support"><em title=support>supported</em></a> by a font in the
jdaggett@8397 3401 font list and attempt to match the remaining combining characters
jdaggett@6701 3402 separately using the rules for single characters.
jdaggett@6701 3403 </ol>
jdaggett@6701 3404
jdaggett@7309 3405 <h3 id=char-handling-issues><span class=secno>5.4 </span>Character handling
jdaggett@2457 3406 issues</h3>
jdaggett@2457 3407
jdaggett@8430 3408 <p>CSS font matching is always performed on text runs containing Unicode
jdaggett@8430 3409 characters, so documents using legacy encodings are assumed to have been
jdaggett@7311 3410 transcoded before matching fonts. For fonts containing <a
jdaggett@7311 3411 href="#character-map"><em title="character map">character maps</em></a>
jdaggett@7311 3412 for both legacy encodings and Unicode, the contents of the legacy encoding
jdaggett@7311 3413 <a href="#character-map"><em>character map</em></a> must have no effect on
jdaggett@7311 3414 the results of the font matching process.
jdaggett@2461 3415
jdaggett@2461 3416 <p>The font matching process does not assume that text runs are in either
jdaggett@2461 3417 normalized or denormalized form (see <a href="#CHARMOD-NORM"
jdaggett@3042 3418 rel=biblioentry>[CHARMOD-NORM]<!--{{CHARMOD-NORM}}--></a> for more
jdaggett@8430 3419 details). Fonts may only support precomposed forms and not the decomposed
jdaggett@8430 3420 sequence of base character plus combining marks. Authors should always
jdaggett@6701 3421 tailor their choice of fonts to their content, including whether that
jdaggett@6701 3422 content contains normalized or denormalized character streams.
jdaggett@2457 3423
jdaggett@8430 3424 <p>If a given character is a Private-Use Area Unicode codepoint, user
jdaggett@8430 3425 agents must only match font families named in the ‘<code
jdaggett@8430 3426 class=property>font-family</code>’ list that are not generic families.
jdaggett@8430 3427 If none of the families named in the ‘<code
jdaggett@8430 3428 class=property>font-family</code>’ list contain a glyph for that
jdaggett@8430 3429 codepoint, user agents must display some form of missing glyph symbol for
jdaggett@8430 3430 that character rather than attempting <a
jdaggett@8430 3431 href="#system-font-fallback"><em>system font fallback</em></a> for that
jdaggett@8430 3432 codepoint. When matching the replacement character U+FFFD, user agents may
jdaggett@8430 3433 skip the font matching process and immediately display some form of
jdaggett@8430 3434 missing glyph symbol, they are not required to display the glyph from the
jdaggett@8430 3435 font that would be selected by the font matching process.
jdaggett@2457 3436
jdaggett@2457 3437 <p>In general, the fonts for a given family will all have the same or
jdaggett@7311 3438 similar <a href="#character-map"><em title="character map">character
jdaggett@7311 3439 maps</em></a>. The process outlined here is designed to handle even font
jdaggett@7311 3440 families containing faces with widely variant <a href="#character-map"><em
jdaggett@7311 3441 title="character map">character maps</em></a>. However, authors are
jdaggett@7311 3442 cautioned that the use of such families can lead to unexpected results.
jdaggett@2457 3443
jdaggett@7309 3444 <h3 id=font-matching-changes><span class=secno>5.5 </span>Font matching
jdaggett@2509 3445 changes since CSS 2.1</h3>
jdaggett@2509 3446
jdaggett@2509 3447 <p>The algorithm above is different from CSS 2.1 in a number of key places.
jdaggett@2509 3448 These changes were made to better reflect actual font matching behavior
jdaggett@2509 3449 across user agent implementations.
jdaggett@2509 3450
jdaggett@2509 3451 <p>Differences compared to the font matching algorithm in CSS 2.1:
jdaggett@2509 3452
jdaggett@2509 3453 <ul>
jdaggett@2509 3454 <li>The algorithm includes font-stretch matching.
jdaggett@2509 3455
jdaggett@2509 3456 <li>All possible font-style matching scenarios are delineated.
jdaggett@2509 3457
jdaggett@2509 3458 <li>Small-caps fonts are not matched as part of the font matching process,
jdaggett@2509 3459 they are now handled via font features.
jdaggett@2509 3460
jdaggett@2509 3461 <li>Unicode variation selector matching is required.
jdaggett@6701 3462
jdaggett@6701 3463 <li>Cluster sequences are matched as a unit.
jdaggett@2509 3464 </ul>
jdaggett@531 3465
jdaggett@7309 3466 <h3 id=font-matching-examples><span class=secno>5.6 </span>Font matching
jdaggett@6701 3467 examples</h3>
jdaggett@6701 3468
jdaggett@531 3469 <div class=example>
jdaggett@531 3470 <p>It's useful to note that the CSS selector syntax may be used to create
jdaggett@531 3471 language-sensitive typography. For example, some Chinese and Japanese
jdaggett@1149 3472 characters are unified to have the same Unicode code point, although the
jdaggett@890 3473 abstract glyphs are not the same in the two languages.
jdaggett@531 3474
jdaggett@531 3475 <pre>*:lang(ja-jp) { font: 900 14pt/16pt &quot;Heisei Mincho W9&quot;, serif; }
jdaggett@531 3476 *:lang(zh-tw) { font: 800 14pt/16.5pt &quot;Li Sung&quot;, serif; }
jdaggett@512 3477 </pre>
jdaggett@531 3478
jdaggett@8430 3479 <p>This selects any element that has the given language — Japanese or
jdaggett@8430 3480 Traditional Chinese — and uses the appropriate font.
jdaggett@512 3481 </div>
jdaggett@1662 3482
jdaggett@6699 3483 <h2 id=font-rend-props><span class=secno>6 </span>Font Feature Properties</h2>
jdaggett@1662 3484
jdaggett@1856 3485 <p>Modern font technologies support a variety of advanced typographic and
jdaggett@1856 3486 language-specific font features. Using these features, a single font can
jdaggett@1856 3487 provide glyphs for a wide range of ligatures, contextual and stylistic
jdaggett@1856 3488 alternates, tabular and old-style figures, small capitals, automatic
jdaggett@1856 3489 fractions, swashes, and alternates specific to a given language. To allow
jdaggett@8313 3490 authors control over these font capabilities, the ‘<code
jdaggett@8313 3491 class=property>font-variant</code>’ property has been expanded for CSS3.
jdaggett@8313 3492 It now functions as a shorthand for a set of properties that provide
jdaggett@8313 3493 control over stylistic font features.
jdaggett@1856 3494
jdaggett@1856 3495 <h3 id=glyph-selection-positioning><span class=secno>6.1 </span>Glyph
jdaggett@1856 3496 selection and positioning</h3>
jdaggett@1856 3497
jdaggett@1856 3498 <p>Simple fonts used for displaying Latin text use a very basic processing
jdaggett@8313 3499 model. Fonts contain a <a href="#character-map"><em>character map</em></a>
jdaggett@8313 3500 which maps each character to a glyph for that character. Glyphs for
jdaggett@8313 3501 subsequent characters are simply placed one after the other along a run of
jdaggett@8313 3502 text. Modern font formats such as OpenType and AAT (Apple Advanced
jdaggett@8313 3503 Typography) use a richer processing model. The glyph for a given character
jdaggett@8313 3504 can be chosen and positioned not just based on the codepoint of the
jdaggett@8313 3505 character itself, but also on adjacent characters as well as the language,
jdaggett@8313 3506 script, and features enabled for the text. Font features may be required
jdaggett@8313 3507 for specific scripts, or recommended as enabled by default or they might
jdaggett@8313 3508 be stylistic features meant to be used under author control.
jdaggett@1856 3509
jdaggett@1856 3510 <p>For a good visual overview of these features, see the <a
jdaggett@1856 3511 href="#OPENTYPE-FONT-GUIDE"
jdaggett@1856 3512 rel=biblioentry>[OPENTYPE-FONT-GUIDE]<!--{{OPENTYPE-FONT-GUIDE}}--></a>.
jdaggett@1856 3513 For a detailed description of glyph processing for OpenType fonts, see <a
jdaggett@1856 3514 href="#WINDOWS-GLYPH-PROC"
jdaggett@1856 3515 rel=biblioentry>[WINDOWS-GLYPH-PROC]<!--{{WINDOWS-GLYPH-PROC}}--></a>.
jdaggett@1856 3516
jdaggett@8313 3517 <p>Stylistic font features can be classified into two broad categories:
jdaggett@6177 3518 ones that affect the harmonization of glyph shapes with the surrounding
jdaggett@8313 3519 context, such as kerning and ligature features, and ones such as the
jdaggett@6177 3520 small-caps, subscript/superscript and alternate features that affect shape
jdaggett@6177 3521 selection.
jdaggett@6176 3522
jdaggett@8313 3523 <p>The subproperties of <a href="#propdef-font-variant"
jdaggett@8313 3524 title="font-variant!!property">‘<code
jdaggett@8313 3525 class=property>font-variant</code>’</a> listed below are used to control
jdaggett@8313 3526 these stylistic font features. They do not control features that are
jdaggett@8313 3527 required for displaying certain scripts, such as the OpenType features
jdaggett@8313 3528 used when displaying Arabic or Indic language text. They affect glyph
jdaggett@8313 3529 selection and positioning, but do not affect font selection as described
jdaggett@8313 3530 in the font matching section (except in cases required for compatibility
jdaggett@8313 3531 with CSS 2.1).
jdaggett@1856 3532
jdaggett@1856 3533 <p>To assure consistent behavior across user agents, the equivalent
jdaggett@8313 3534 OpenType property settings are listed for individual properties and are
jdaggett@8313 3535 normative. When using other font formats these should be used as a
jdaggett@8313 3536 guideline to map CSS font feature property values to specific font
jdaggett@8313 3537 features.
jdaggett@1856 3538
jdaggett@1856 3539 <h3 id=language-specific-support><span class=secno>6.2
jdaggett@1856 3540 </span>Language-specific display</h3>
jdaggett@1856 3541
jdaggett@1856 3542 <p>OpenType also supports language-specific glyph selection and
jdaggett@1856 3543 positioning, so that text can be displayed correctly in cases where the
jdaggett@8313 3544 language dictates a specific display behavior. Many languages share a
jdaggett@8313 3545 common script, but the shape of certain letters can vary across those
jdaggett@8313 3546 languages. For example, certain Cyrillic letters have different shapes in
jdaggett@8313 3547 Russian text than in Bulgarian. In Latin text, it's common to render "fi"
jdaggett@8313 3548 with an explicit fi-ligature that lacks a dot on the "i". However, in
jdaggett@8313 3549 languages such as Turkish which uses both a dotted-i and a dotless-i, it's
jdaggett@8313 3550 important to not use this ligature or use a specialized version that
jdaggett@8313 3551 contains a dot over the "i". The example below shows language-specific
jdaggett@8313 3552 variations based on stylistic traditions found in Spanish, Italian and
jdaggett@8313 3553 French orthography:
jdaggett@2515 3554
jdaggett@2515 3555 <div class=featex><img alt="language specific forms, spanish"
jdaggett@2515 3556 src=locl-1.png></div>
jdaggett@2515 3557
jdaggett@2515 3558 <div class=featex><img alt="language specific forms, italian"
jdaggett@2515 3559 src=locl-2.png></div>
jdaggett@2515 3560
jdaggett@2515 3561 <div class=featex><img alt="language specific forms, french"
jdaggett@2515 3562 src=locl-3.png></div>
jdaggett@1856 3563
jdaggett@8313 3564 <p>If the content language of the element is known according to the rules
jdaggett@7355 3565 of the <a
jdaggett@7355 3566 href="http://www.w3.org/TR/CSS21/conform.html#doclanguage">document
jdaggett@7355 3567 language</a>, user agents are required to infer the OpenType language
jdaggett@7355 3568 system from the content language and use that when selecting and
jdaggett@7355 3569 positioning glyphs using an OpenType font.
jdaggett@7355 3570
jdaggett@7355 3571 <p>For OpenType fonts, in some cases it may be necessary to explicitly
jdaggett@7355 3572 declare the OpenType language to be used, for example when displaying text
jdaggett@7355 3573 in a given language that uses the typographic conventions of another
jdaggett@7355 3574 language or when the font does not explicitly support a given language but
jdaggett@7355 3575 supports a language that shares common typographic conventions. The ‘<a
jdaggett@4624 3576 href="#propdef-font-language-override"><code
jdaggett@4624 3577 class=property>font-language-override</code></a>’ property is used for
jdaggett@8225 3578 this purpose.</p>
jdaggett@1662 3579 <!-- prop: font-kerning -->
jdaggett@1662 3580
jdaggett@1856 3581 <h3 id=font-kerning-prop><span class=secno>6.3 </span>Kerning: the <a
jdaggett@1662 3582 href="#propdef-font-kerning">font-kerning</a> property</h3>
jdaggett@1662 3583
jdaggett@4624 3584 <table class=propdef id=namefont-kerningvalueauto-normal-noneini>
jdaggett@1662 3585 <tbody>
jdaggett@1662 3586 <tr>
jdaggett@1662 3587 <td>Name:
jdaggett@1662 3588
jdaggett@1662 3589 <td><dfn id=propdef-font-kerning>font-kerning</dfn>
jdaggett@1662 3590
jdaggett@1662 3591 <tr>
jdaggett@1662 3592 <td>Value:
jdaggett@1662 3593
jdaggett@8278 3594 <td><a href="#font-kerning-auto-value"
jdaggett@8278 3595 title="auto!!font-kerning">auto</a> | <a
jdaggett@8278 3596 href="#font-kerning-normal-value"
jdaggett@8278 3597 title="normal!!font-kerning">normal</a> | <a
jdaggett@8278 3598 href="#font-kerning-none-value" title="none!!font-kerning">none</a>
jdaggett@1662 3599
jdaggett@1662 3600 <tr>
jdaggett@1662 3601 <td>Initial:
jdaggett@1662 3602
jdaggett@1856 3603 <td>auto
jdaggett@1662 3604
jdaggett@1662 3605 <tr>
jdaggett@1662 3606 <td>Applies to:
jdaggett@1662 3607
jdaggett@1662 3608 <td>all elements
jdaggett@1662 3609
jdaggett@1662 3610 <tr>
jdaggett@1662 3611 <td>Inherited:
jdaggett@1662 3612
jdaggett@1662 3613 <td>yes
jdaggett@1662 3614
jdaggett@1662 3615 <tr>
jdaggett@1662 3616 <td>Percentages:
jdaggett@1662 3617
jdaggett@1662 3618 <td>N/A
jdaggett@1662 3619
jdaggett@1662 3620 <tr>
jdaggett@1662 3621 <td>Media:
jdaggett@1662 3622
jdaggett@1662 3623 <td>visual
jdaggett@1662 3624
jdaggett@1662 3625 <tr>
jdaggett@1662 3626 <td>Computed value:
jdaggett@1662 3627
jdaggett@1662 3628 <td>as specified
jdaggett@7377 3629
jdaggett@7377 3630 <tr>
jdaggett@7377 3631 <td>Animatable:
jdaggett@7377 3632
jdaggett@7377 3633 <td>no
jdaggett@1662 3634 </table>
jdaggett@1662 3635
jdaggett@2509 3636 <p>Kerning is the contextual adjustment of inter-glyph spacing. This
jdaggett@2509 3637 property controls metric kerning, kerning that utilizes adjustment data
jdaggett@8276 3638 contained in the font.
jdaggett@8276 3639
jdaggett@8276 3640 <dl>
jdaggett@8278 3641 <dt><dfn id=font-kerning-auto-value title="auto!!font-kerning">auto</dfn>
jdaggett@8276 3642
jdaggett@8276 3643 <dd>Specifies that kerning is applied at the discretion of the user agent
jdaggett@8276 3644
jdaggett@8278 3645 <dt><dfn id=font-kerning-normal-value
jdaggett@8278 3646 title="normal!!font-kerning">normal</dfn>
jdaggett@8276 3647
jdaggett@8276 3648 <dd>Specifies that kerning is applied
jdaggett@8276 3649
jdaggett@8278 3650 <dt><dfn id=font-kerning-none-value title="none!!font-kerning">none</dfn>
jdaggett@8276 3651
jdaggett@8276 3652 <dd>Specifies that kerning is not applied
jdaggett@8276 3653 </dl>
jdaggett@1662 3654
jdaggett@1662 3655 <p>For fonts that do not include kerning data this property will have no
jdaggett@1662 3656 visible effect. When rendering with OpenType fonts, the <a
jdaggett@1662 3657 href="#OPENTYPE" rel=biblioentry>[OPENTYPE]<!--{{!OPENTYPE}}--></a>
jdaggett@2515 3658 specification suggests that kerning be enabled by default. When kerning is
jdaggett@6436 3659 enabled, the OpenType <span class=tag>kern</span> feature is enabled (for
jdaggett@8276 3660 vertical text runs the <span class=tag>vkrn</span> feature is enabled
jdaggett@8276 3661 instead). User agents must also support fonts that only support kerning
jdaggett@8276 3662 via data contained in a <span class=tag>kern</span> font table, as
jdaggett@8276 3663 detailed in the OpenType specification. If the ‘<code
jdaggett@8276 3664 class=property>letter-spacing</code>’ property is defined, kerning
jdaggett@8276 3665 adjustments are considered part of the default spacing and letter spacing
jdaggett@8276 3666 adjustments are made after kerning has been applied.
jdaggett@8276 3667
jdaggett@8276 3668 <p>When set to ‘<code class=property>auto</code>’, user agents can
jdaggett@8276 3669 determine whether to apply kerning or not based on a number of factors:
jdaggett@8276 3670 text size, script, or other factors that influence text processing speed.
jdaggett@8368 3671 Authors who want proper kerning should use <a
jdaggett@8368 3672 href="#font-kerning-normal-value" title="normal!!font-kerning">‘<code
jdaggett@8368 3673 class=property>normal</code>’</a> to explicitly enable kerning.
jdaggett@8279 3674 Likewise, some authors may prefer to disable kerning in situations where
jdaggett@8279 3675 performance is more important than precise appearance. However, in
jdaggett@8279 3676 well-designed modern implementations the use of kerning generally does not
jdaggett@8279 3677 have a large impact on text rendering speed.</p>
jdaggett@6176 3678 <!-- prop: font-variant-ligatures -->
jdaggett@6176 3679
jdaggett@6176 3680 <h3 id=font-variant-ligatures-prop><span class=secno>6.4 </span>Ligatures:
jdaggett@6176 3681 the <a href="#propdef-font-variant-ligatures">font-variant-ligatures</a>
jdaggett@6176 3682 property</h3>
jdaggett@6176 3683
jdaggett@6436 3684 <table class=propdef id=namefont-variant-ligaturesvaluenormal-no>
jdaggett@6176 3685 <tbody>
jdaggett@6176 3686 <tr>
jdaggett@6176 3687 <td>Name:
jdaggett@6176 3688
jdaggett@6176 3689 <td><dfn id=propdef-font-variant-ligatures>font-variant-ligatures</dfn>
jdaggett@6176 3690
jdaggett@6176 3691 <tr>
jdaggett@6176 3692 <td>Value:
jdaggett@6176 3693
jdaggett@8278 3694 <td><a href="#font-variant-ligatures-normal-value"
jdaggett@8278 3695 title="normal!!font-variant-ligatures">normal</a> | <a
jdaggett@8278 3696 href="#font-variant-ligatures-none-value"
jdaggett@8278 3697 title="none!!font-variant-ligatures">none</a> | [ <a
jdaggett@8225 3698 href="#common-lig-values"><var>&lt;common-lig-values&gt;</var></a> ||
jdaggett@8225 3699 <a
jdaggett@8225 3700 href="#discretionary-lig-values"><var>&lt;discretionary-lig-values&gt;</var></a>
jdaggett@8225 3701 || <a
jdaggett@8225 3702 href="#historical-lig-values"><var>&lt;historical-lig-values&gt;</var></a>
jdaggett@8225 3703 || <a
jdaggett@8225 3704 href="#contextual-alt-values"><var>&lt;contextual-alt-values&gt;</var></a>
jdaggett@8225 3705 ]
jdaggett@6176 3706
jdaggett@6176 3707 <tr>
jdaggett@6176 3708 <td>Initial:
jdaggett@6176 3709
jdaggett@6176 3710 <td>normal
jdaggett@6176 3711
jdaggett@6176 3712 <tr>
jdaggett@6176 3713 <td>Applies to:
jdaggett@6176 3714
jdaggett@6176 3715 <td>all elements
jdaggett@6176 3716
jdaggett@6176 3717 <tr>
jdaggett@6176 3718 <td>Inherited:
jdaggett@6176 3719
jdaggett@6176 3720 <td>yes
jdaggett@6176 3721
jdaggett@6176 3722 <tr>
jdaggett@6176 3723 <td>Percentages:
jdaggett@6176 3724
jdaggett@6176 3725 <td>N/A
jdaggett@6176 3726
jdaggett@6176 3727 <tr>
jdaggett@6176 3728 <td>Media:
jdaggett@6176 3729
jdaggett@6176 3730 <td>visual
jdaggett@6176 3731
jdaggett@6176 3732 <tr>
jdaggett@6176 3733 <td>Computed value:
jdaggett@6176 3734
jdaggett@6176 3735 <td>as specified
jdaggett@7377 3736
jdaggett@7377 3737 <tr>
jdaggett@7377 3738 <td>Animatable:
jdaggett@7377 3739
jdaggett@7377 3740 <td>no
jdaggett@6176 3741 </table>
jdaggett@6176 3742
jdaggett@6436 3743 <p>Ligatures and contextual forms are ways of combining glyphs to produce
jdaggett@8276 3744 more harmonized forms.
jdaggett@6176 3745
jdaggett@6176 3746 <pre
jdaggett@8225 3747 class=prod><dfn id=common-lig-values><var>&lt;common-lig-values&gt;</var></dfn> = [ <a href="#common-ligatures">common-ligatures</a> | <a href="#no-common-ligatures">no-common-ligatures</a> ]</pre>
jdaggett@6176 3748
jdaggett@6176 3749 <pre
jdaggett@8225 3750 class=prod><dfn id=discretionary-lig-values><var>&lt;discretionary-lig-values&gt;</var></dfn> = [ <a href="#discretionary-ligatures">discretionary-ligatures</a> | <a href="#no-discretionary-ligatures">no-discretionary-ligatures</a> ]</pre>
jdaggett@6176 3751
jdaggett@6176 3752 <pre
jdaggett@8225 3753 class=prod><dfn id=historical-lig-values><var>&lt;historical-lig-values&gt;</var></dfn> = [ <a href="#historical-ligatures">historical-ligatures</a> | <a href="#no-historical-ligatures">no-historical-ligatures</a> ]</pre>
jdaggett@6176 3754
jdaggett@6176 3755 <pre
jdaggett@8225 3756 class=prod><dfn id=contextual-alt-values><var>&lt;contextual-alt-values&gt;</var></dfn> = [ <a href="#contextual">contextual</a> | <a href="#no-contextual">no-contextual</a> ]</pre>
jdaggett@6176 3757
jdaggett@6176 3758 <p>Individual values have the following meanings:
jdaggett@6176 3759
jdaggett@6176 3760 <dl>
jdaggett@8278 3761 <dt><dfn id=font-variant-ligatures-normal-value
jdaggett@8278 3762 title="normal!!font-variant-ligatures">normal</dfn>
jdaggett@8278 3763
jdaggett@8368 3764 <dd>A value of <a href="#font-variant-ligatures-normal-value"
jdaggett@8368 3765 title="normal!!font-variant-ligatures">‘<code
jdaggett@8368 3766 class=property>normal</code>’</a> specifies that common default
jdaggett@8279 3767 features are enabled, <a href="#font-feature-resolution">as described in
jdaggett@8279 3768 detail in the next section</a>. For OpenType fonts, common ligatures and
jdaggett@8279 3769 contextual forms are on by default, discretionary and historical
jdaggett@8279 3770 ligatures are not.
jdaggett@8278 3771
jdaggett@8278 3772 <dt><dfn id=font-variant-ligatures-none-value
jdaggett@8278 3773 title="none!!font-variant-ligatures">none</dfn>
jdaggett@8276 3774
jdaggett@8276 3775 <dd>Specifies that all types of ligatures and contextual forms covered by
jdaggett@8276 3776 this property are explicitly disabled. In situations where ligatures are
jdaggett@8276 3777 not considered necessary, this may improve the speed of text rendering.
jdaggett@8276 3778
jdaggett@6176 3779 <dt><dfn id=common-ligatures>common-ligatures</dfn>
jdaggett@6176 3780
jdaggett@6436 3781 <dd>Enables display of common ligatures (OpenType features: <span
jdaggett@6436 3782 class=tag>liga, clig</span>). For OpenType fonts, common ligatures are
jdaggett@6436 3783 enabled by default.
jdaggett@6176 3784 </dl>
jdaggett@6176 3785
jdaggett@6176 3786 <div class=featex><img alt="common ligature example" src=liga.png></div>
jdaggett@6176 3787
jdaggett@6176 3788 <dl>
jdaggett@6176 3789 <dt><dfn id=no-common-ligatures>no-common-ligatures</dfn>
jdaggett@6176 3790
jdaggett@6436 3791 <dd>Disables display of common ligatures (OpenType features: <span
jdaggett@6436 3792 class=tag>liga, clig</span>).
jdaggett@6176 3793
jdaggett@6176 3794 <dt><dfn id=discretionary-ligatures>discretionary-ligatures</dfn>
jdaggett@6176 3795
jdaggett@6436 3796 <dd>Enables display of discretionary ligatures (OpenType feature: <span
jdaggett@8277 3797 class=tag>dlig</span>). Which ligatures are discretionary or optional is
jdaggett@8277 3798 decided by the type designer, so authors will need to refer to the
jdaggett@6176 3799 documentation of a given font to understand which ligatures are
jdaggett@6176 3800 considered discretionary.
jdaggett@6176 3801 </dl>
jdaggett@6176 3802
jdaggett@6176 3803 <div class=featex><img alt="discretionary ligature example" src=dlig.png></div>
jdaggett@6176 3804
jdaggett@6176 3805 <dl>
jdaggett@6176 3806 <dt><dfn id=no-discretionary-ligatures>no-discretionary-ligatures</dfn>
jdaggett@6176 3807
jdaggett@6436 3808 <dd>Disables display of discretionary ligatures (OpenType feature: <span
jdaggett@6436 3809 class=tag>dlig</span>).
jdaggett@6176 3810
jdaggett@6176 3811 <dt><dfn id=historical-ligatures>historical-ligatures</dfn>
jdaggett@6176 3812
jdaggett@6436 3813 <dd>Enables display of historical ligatures (OpenType feature: <span
jdaggett@6436 3814 class=tag>hlig</span>).
jdaggett@6176 3815 </dl>
jdaggett@6176 3816
jdaggett@6176 3817 <div class=featex><img alt="historical ligature example" src=hlig.png></div>
jdaggett@6176 3818
jdaggett@6176 3819 <dl>
jdaggett@6176 3820 <dt><dfn id=no-historical-ligatures>no-historical-ligatures</dfn>
jdaggett@6176 3821
jdaggett@6436 3822 <dd>Disables display of historical ligatures (OpenType feature: <span
jdaggett@6436 3823 class=tag>hlig</span>).
jdaggett@6176 3824
jdaggett@6176 3825 <dt><dfn id=contextual>contextual</dfn>
jdaggett@6176 3826
jdaggett@6436 3827 <dd>Enables display of contextual alternates (OpenType feature: <span
jdaggett@6436 3828 class=tag>calt</span>). Although not strictly a ligature feature, like
jdaggett@6176 3829 ligatures this feature is commonly used to harmonize the shapes of glyphs
jdaggett@6436 3830 with the surrounding context. For OpenType fonts, this feature is on by
jdaggett@6436 3831 default.
jdaggett@6176 3832 </dl>
jdaggett@6176 3833
jdaggett@6176 3834 <div class=featex><img alt="contextual alternate example" src=calt.png></div>
jdaggett@6176 3835
jdaggett@6176 3836 <dl>
jdaggett@6176 3837 <dt><dfn id=no-contextual>no-contextual</dfn>
jdaggett@6176 3838
jdaggett@6436 3839 <dd>Disables display of contextual alternates (OpenType feature: <span
jdaggett@6436 3840 class=tag>calt</span>).
jdaggett@6176 3841 </dl>
jdaggett@6176 3842
jdaggett@6176 3843 <p>Required ligatures, needed for correctly rendering complex scripts, are
jdaggett@8278 3844 not affected by the settings above, including ‘<code
jdaggett@8278 3845 class=property>none</code>’ (OpenType feature: <span
jdaggett@6436 3846 class=tag>rlig</span>).</p>
jdaggett@3460 3847 <!-- prop: font-variant-position -->
jdaggett@3460 3848
jdaggett@6176 3849 <h3 id=font-variant-position-prop><span class=secno>6.5 </span>Subscript
jdaggett@3638 3850 and superscript forms: the <a
jdaggett@3460 3851 href="#propdef-font-variant-position">font-variant-position</a> property</h3>
jdaggett@3460 3852
jdaggett@4624 3853 <table class=propdef id=namefont-variant-positionvaluenormal-sub>
jdaggett@1662 3854 <tbody>
jdaggett@1662 3855 <tr>
jdaggett@1662 3856 <td>Name:
jdaggett@1662 3857
jdaggett@3460 3858 <td><dfn id=propdef-font-variant-position>font-variant-position</dfn>
jdaggett@1662 3859
jdaggett@1662 3860 <tr>
jdaggett@1662 3861 <td>Value:
jdaggett@1662 3862
jdaggett@8368 3863 <td><a href="#font-variant-position-normal-value"
jdaggett@8368 3864 title="normal!!font-variant-position">normal</a> | <a
jdaggett@8279 3865 href="#sub">sub</a> | <a href="#super">super</a>
jdaggett@1732 3866
jdaggett@1732 3867 <tr>
jdaggett@1732 3868 <td>Initial:
jdaggett@1732 3869
jdaggett@1732 3870 <td>normal
jdaggett@1732 3871
jdaggett@1732 3872 <tr>
jdaggett@1732 3873 <td>Applies to:
jdaggett@1732 3874
jdaggett@1732 3875 <td>all elements
jdaggett@1732 3876
jdaggett@1732 3877 <tr>
jdaggett@1732 3878 <td>Inherited:
jdaggett@1732 3879
jdaggett@1732 3880 <td>yes
jdaggett@1732 3881
jdaggett@1732 3882 <tr>
jdaggett@1732 3883 <td>Percentages:
jdaggett@1732 3884
jdaggett@1732 3885 <td>N/A
jdaggett@1732 3886
jdaggett@1732 3887 <tr>
jdaggett@1732 3888 <td>Media:
jdaggett@1732 3889
jdaggett@1732 3890 <td>visual
jdaggett@1732 3891
jdaggett@1732 3892 <tr>
jdaggett@1732 3893 <td>Computed value:
jdaggett@1732 3894
jdaggett@1732 3895 <td>as specified
jdaggett@7377 3896
jdaggett@7377 3897 <tr>
jdaggett@7377 3898 <td>Animatable:
jdaggett@7377 3899
jdaggett@7377 3900 <td>no
jdaggett@1732 3901 </table>
jdaggett@1732 3902
jdaggett@5890 3903 <p>This property is used to enable typographic subscript and superscript
jdaggett@5890 3904 glyphs. These are alternate glyphs designed within the same em-box as
jdaggett@5890 3905 default glyphs and are intended to be laid out on the same baseline as the
jdaggett@5890 3906 default glyphs, with no resizing or repositioning of the baseline. They
jdaggett@5890 3907 are explicitly designed to match the surrounding text and to be more
jdaggett@5890 3908 readable without affecting the line height.
jdaggett@3511 3909
jdaggett@3511 3910 <div class=figure><img alt="comparison between real subscript glyphs and
jdaggett@3511 3911 synthesized ones" src=realsubscripts.png>
jdaggett@3511 3912 <p class=caption>Subscript glyphs (top) vs. typical synthesized subscripts
jdaggett@3511 3913 (bottom)
jdaggett@3511 3914 </div>
jdaggett@3460 3915
jdaggett@8279 3916 <p>Individual values have the following meanings:
jdaggett@8279 3917
jdaggett@8279 3918 <dl>
jdaggett@8368 3919 <dt><dfn id=font-variant-position-normal-value
jdaggett@8368 3920 title="normal!!font-variant-position">normal</dfn>
jdaggett@8279 3921
jdaggett@8279 3922 <dd>None of the features listed below are enabled.
jdaggett@8279 3923
jdaggett@8279 3924 <dt><dfn id=sub>sub</dfn>
jdaggett@8279 3925
jdaggett@8279 3926 <dd>Enables display of subscript variants (OpenType feature: <span
jdaggett@8279 3927 class=tag>subs</span>).
jdaggett@8279 3928
jdaggett@8279 3929 <dt><dfn id=super>super</dfn>
jdaggett@8279 3930
jdaggett@8279 3931 <dd>Enables display of superscript variants (OpenType feature: <span
jdaggett@8279 3932 class=tag>sups</span>).
jdaggett@8279 3933 </dl>
jdaggett@5890 3934
jdaggett@5890 3935 <p>Because of the semantic nature of subscripts and superscripts, when the
jdaggett@8279 3936 value is either ‘<a href="#sub"><code class=property>sub</code></a>’
jdaggett@8279 3937 or ‘<a href="#super"><code class=property>super</code></a>’ for a
jdaggett@8279 3938 given contiguous run of text, if a variant glyph is not available for all
jdaggett@8279 3939 the characters in the run, simulated glyphs must be synthesized for all
jdaggett@8279 3940 characters using reduced forms of the glyphs that would be used without
jdaggett@8280 3941 this feature applied. This is done per run to avoid a mixture of variant
jdaggett@8280 3942 glyphs and synthesized ones that would not align correctly. In the case of
jdaggett@8280 3943 OpenType fonts that lack subscript or superscript glyphs for a given
jdaggett@8280 3944 character, user agents must use the appropriate subscript and superscript
jdaggett@8280 3945 metrics specified in the selected font's <a
jdaggett@3460 3946 href="http://www.microsoft.com/typography/otspec/os2.htm#subxs">OS/2
jdaggett@3460 3947 table</a> <a href="#OPENTYPE"
jdaggett@5891 3948 rel=biblioentry>[OPENTYPE]<!--{{!OPENTYPE}}--></a> to calculate the size
jdaggett@5891 3949 and offset of the synthesized substitutes.
jdaggett@2461 3950
jdaggett@8280 3951 <div class=figure><img alt="alternate superscripts vs. glyphs synthesized
jdaggett@8280 3952 using superscript metrics" src=superscript-alt-synth.png>
jdaggett@8280 3953 <p class=caption>Superscript alternate glyph (left), synthesized
jdaggett@8280 3954 superscript glyphs (middle), and incorrect mixture of the two (right)
jdaggett@8280 3955 </div>
jdaggett@8280 3956
jdaggett@8385 3957 <p>In situations where text decorations are only applied to runs of text
jdaggett@8385 3958 containing superscript or subscript glyphs, the synthesized glyphs must be
jdaggett@8385 3959 used to avoid problems with the placement of decorations.
jdaggett@8385 3960
jdaggett@2461 3961 <p>In the past, user agents have used font-size and vertical-align to
jdaggett@8368 3962 simulate subscripts and superscripts for the <code title="HTML sub
jdaggett@8368 3963 element">sub</code> and <code title="HTML sup element">sup</code>
jdaggett@8368 3964 elements. To allow a backwards compatible way of defining subscripts and
jdaggett@8368 3965 superscripts, it is recommended that authors use conditional rules <a
jdaggett@8368 3966 href="#CSS3-CONDITIONAL"
jdaggett@3460 3967 rel=biblioentry>[CSS3-CONDITIONAL]<!--{{CSS3-CONDITIONAL}}--></a> so that
jdaggett@5890 3968 older user agents will still render subscripts and superscripts via the
jdaggett@5890 3969 older mechanism.
jdaggett@5890 3970
jdaggett@5890 3971 <p>Authors should note that fonts typically only provide subscript and
jdaggett@5890 3972 superscript glyphs for a subset of all characters supported by the font.
jdaggett@8280 3973 For example, while subscript and superscript glyphs are often available
jdaggett@8280 3974 for Latin numbers, glyphs for punctuation and letter characters are less
jdaggett@8280 3975 frequently provided. The synthetic fallback rules defined for this
jdaggett@8280 3976 property assure that subscripts and superscripts will always appear but
jdaggett@8280 3977 the appearance may not match author expectations if the font used does not
jdaggett@8280 3978 provide the appropriate alternate glyph for all characters contained in a
jdaggett@8280 3979 subscript or superscript.
jdaggett@8280 3980
jdaggett@8280 3981 <p>This property is not cumulative. Applying it to elements within a
jdaggett@5890 3982 subscript or superscript won't nest the placement of a subscript or
jdaggett@5890 3983 superscript glyph. Images contained within text runs where the value of
jdaggett@8279 3984 this property is ‘<a href="#sub"><code class=property>sub</code></a>’
jdaggett@8279 3985 or ‘<a href="#super"><code class=property>super</code></a>’ will be
jdaggett@8368 3986 drawn just as they would if the value was <a
jdaggett@8368 3987 href="#font-variant-position-normal-value"
jdaggett@8368 3988 title="normal!!font-variant-position">‘<code
jdaggett@8368 3989 class=property>normal</code>’</a>.</p>
jdaggett@8364 3990 <!-- due to lack of consensus, couldn't resolve on exact positioning of text decorations:
jdaggett@8364 3991 http://www.w3.org/2013/06/06-css-minutes.html#item03 -->
jdaggett@8280 3992
jdaggett@8280 3993 <p>Because of these limitations, ‘<a
jdaggett@8280 3994 href="#propdef-font-variant-position"><code
jdaggett@8280 3995 class=property>font-variant-position</code></a>’ is not recommended for
jdaggett@8280 3996 use in user agent stylesheets. Authors should use it in cases where
jdaggett@5890 3997 subscripts or superscripts will only contain the narrow range of
jdaggett@5890 3998 characters supported by the fonts specified.
jdaggett@2509 3999
jdaggett@8368 4000 <p class=note>The variant glyphs use the same baseline as the default
jdaggett@8368 4001 glyphs would use. There is no shift in the placement along the baseline,
jdaggett@8368 4002 so the use of variant glyphs doesn't affect the height of the inline box
jdaggett@8368 4003 or alter the height of the linebox. This makes superscript and subscript
jdaggett@8368 4004 variants ideal for situations where it's important that leading remain
jdaggett@8368 4005 constant, such as in multi-column layout.
jdaggett@8368 4006
jdaggett@2461 4007 <div class=example>
jdaggett@8279 4008 <p>A typical user agent default style for the <a class=tag
jdaggett@8279 4009 href="#sub">sub</a> element:</p>
jdaggett@2461 4010
jdaggett@2461 4011 <pre>sub {
jdaggett@2461 4012 vertical-align: sub;
jdaggett@2461 4013 font-size: smaller;
jdaggett@2461 4014 line-height: normal;
jdaggett@2461 4015 }
jdaggett@2461 4016 </pre>
jdaggett@2461 4017
jdaggett@3460 4018 <p>Using font-variant-position to specify typographic subscripts in a way
jdaggett@3460 4019 that will still show subscripts in older user agents:</p>
jdaggett@3460 4020
jdaggett@3460 4021 <pre>@supports ( font-variant-position: sub ) {
jdaggett@3460 4022
jdaggett@3460 4023 sub {
jdaggett@8280 4024 vertical-align: baseline;
jdaggett@3460 4025 font-size: 100%;
jdaggett@3460 4026 line-height: inherit;
jdaggett@3460 4027 font-variant-position: sub;
jdaggett@3460 4028 }
jdaggett@3460 4029
jdaggett@2461 4030 }
jdaggett@2461 4031 </pre>
jdaggett@2461 4032
jdaggett@4624 4033 <p>User agents that support the ‘<a
jdaggett@4624 4034 href="#propdef-font-variant-position"><code
jdaggett@4624 4035 class=property>font-variant-position</code></a>’ property will select a
jdaggett@4624 4036 subscript variant glyph and render this without adjusting the baseline or
jdaggett@4624 4037 font-size. Older user agents will ignore the ‘<a
jdaggett@4624 4038 href="#propdef-font-variant-position"><code
jdaggett@4624 4039 class=property>font-variant-position</code></a>’ property definition
jdaggett@4624 4040 and use the standard defaults for subscripts.</p>
jdaggett@2461 4041 </div>
jdaggett@2118 4042 <!-- prop: font-variant-caps -->
jdaggett@2118 4043
jdaggett@2118 4044 <h3 id=font-variant-caps-prop><span class=secno>6.6 </span>Capitalization:
jdaggett@1662 4045 the <a href="#propdef-font-variant-caps">font-variant-caps</a> property</h3>
jdaggett@1662 4046
jdaggett@5809 4047 <table class=propdef id=namefont-variant-capsvaluenormal-small-c>
jdaggett@1662 4048 <tbody>
jdaggett@1662 4049 <tr>
jdaggett@1662 4050 <td>Name:
jdaggett@1662 4051
jdaggett@1662 4052 <td><dfn id=propdef-font-variant-caps>font-variant-caps</dfn>
jdaggett@1662 4053
jdaggett@1662 4054 <tr>
jdaggett@1662 4055 <td>Value:
jdaggett@1662 4056
jdaggett@8278 4057 <td><a href="#font-variant-caps-normal-value"
jdaggett@8278 4058 title="normal!!font-variant-caps">normal</a> | <a
jdaggett@8278 4059 href="#small-caps">small-caps</a> | <a
jdaggett@8278 4060 href="#all-small-caps">all-small-caps</a> | <a
jdaggett@8278 4061 href="#petite-caps">petite-caps</a> | <a
jdaggett@8278 4062 href="#all-petite-caps">all-petite-caps</a> | <a
jdaggett@8278 4063 href="#unicase">unicase</a> | <a href="#titling-caps">titling-caps</a>
jdaggett@1662 4064
jdaggett@1662 4065 <tr>
jdaggett@1662 4066 <td>Initial:
jdaggett@1662 4067
jdaggett@1662 4068 <td>normal
jdaggett@1662 4069
jdaggett@1662 4070 <tr>
jdaggett@1662 4071 <td>Applies to:
jdaggett@1662 4072
jdaggett@1662 4073 <td>all elements
jdaggett@1662 4074
jdaggett@1662 4075 <tr>
jdaggett@1662 4076 <td>Inherited:
jdaggett@1662 4077
jdaggett@1662 4078 <td>yes
jdaggett@1662 4079
jdaggett@1662 4080 <tr>
jdaggett@1662 4081 <td>Percentages:
jdaggett@1662 4082
jdaggett@1662 4083 <td>N/A
jdaggett@1662 4084
jdaggett@1662 4085 <tr>
jdaggett@1662 4086 <td>Media:
jdaggett@1662 4087
jdaggett@1662 4088 <td>visual
jdaggett@1662 4089
jdaggett@1662 4090 <tr>
jdaggett@1662 4091 <td>Computed value:
jdaggett@1662 4092
jdaggett@1662 4093 <td>as specified
jdaggett@7377 4094
jdaggett@7377 4095 <tr>
jdaggett@7377 4096 <td>Animatable:
jdaggett@7377 4097
jdaggett@7377 4098 <td>no
jdaggett@1662 4099 </table>
jdaggett@1662 4100
jdaggett@8280 4101 <p>This property allows the selection of alternate glyphs used for small or
jdaggett@8280 4102 petite capitals or for titling. These glyphs are specifically designed to
jdaggett@8280 4103 blend well with the surrounding normal glyphs, to maintain the weight and
jdaggett@8280 4104 readability which suffers when text is simply resized to fit this purpose.
jdaggett@1662 4105
jdaggett@1732 4106 <p>Individual values have the following meanings:
jdaggett@1662 4107
jdaggett@1662 4108 <dl>
jdaggett@8278 4109 <dt><dfn id=font-variant-caps-normal-value
jdaggett@8278 4110 title="normal!!font-variant-caps">normal</dfn>
jdaggett@5809 4111
jdaggett@5809 4112 <dd>None of the features listed below are enabled.
jdaggett@5809 4113
jdaggett@1662 4114 <dt><dfn id=small-caps>small-caps</dfn>
jdaggett@1662 4115
jdaggett@6436 4116 <dd>Enables display of small capitals (OpenType feature: <span
jdaggett@6436 4117 class=tag>smcp</span>). Small-caps glyphs typically use the form of
jdaggett@6436 4118 uppercase letters but are reduced to the size of lowercase letters.
jdaggett@1662 4119 </dl>
jdaggett@1662 4120
jdaggett@1662 4121 <div class=featex><img alt="small-caps example" src=smcp.png></div>
jdaggett@1662 4122
jdaggett@1662 4123 <dl>
jdaggett@1732 4124 <dt><dfn id=all-small-caps>all-small-caps</dfn>
jdaggett@1732 4125
jdaggett@1732 4126 <dd>Enables display of small capitals for both upper and lowercase letters
jdaggett@6436 4127 (OpenType features: <span class=tag>c2sc, smcp</span>).
jdaggett@1732 4128
jdaggett@1662 4129 <dt><dfn id=petite-caps>petite-caps</dfn>
jdaggett@1662 4130
jdaggett@6436 4131 <dd>Enables display of petite capitals (OpenType feature: <span
jdaggett@6436 4132 class=tag>pcap</span>).
jdaggett@1662 4133
jdaggett@1732 4134 <dt><dfn id=all-petite-caps>all-petite-caps</dfn>
jdaggett@1732 4135
jdaggett@1732 4136 <dd>Enables display of petite capitals for both upper and lowercase
jdaggett@6436 4137 letters (OpenType features: <span class=tag>c2pc, pcap</span>).
jdaggett@1732 4138
jdaggett@6648 4139 <dt><dfn id=unicase>unicase</dfn>
jdaggett@6648 4140
jdaggett@6648 4141 <dd>Enables display of mixture of small capitals for uppercase letters
jdaggett@6648 4142 with normal lowercase letters (OpenType feature: <span
jdaggett@6648 4143 class=tag>unic</span>).
jdaggett@6648 4144
jdaggett@1662 4145 <dt><dfn id=titling-caps>titling-caps</dfn>
jdaggett@1662 4146
jdaggett@6436 4147 <dd>Enables display of titling capitals (OpenType feature: <span
jdaggett@6436 4148 class=tag>titl</span>). Uppercase letter glyphs are often designed for
jdaggett@6436 4149 use with lowercase letters. When used in all uppercase titling sequences
jdaggett@6436 4150 they can appear too strong. Titling capitals are designed specifically
jdaggett@6436 4151 for this situation.
jdaggett@1662 4152 </dl>
jdaggett@1662 4153
jdaggett@6648 4154 <p>The availability of these glyphs is based on whether a given feature is
jdaggett@6648 4155 defined or not in the feature list of the font. User agents can optionally
jdaggett@6648 4156 decide this on a per-script basis but should explicitly not decide this on
jdaggett@6648 4157 a per-character basis.
jdaggett@6648 4158
jdaggett@6648 4159 <p>Some fonts may only support a subset or none of the features described
jdaggett@6648 4160 for this property. For backwards compatibility with CSS 2.1, if ‘<a
jdaggett@4624 4161 href="#small-caps"><code class=property>small-caps</code></a>’ or ‘<a
jdaggett@4624 4162 href="#all-small-caps"><code class=property>all-small-caps</code></a>’
jdaggett@4624 4163 is specified but small-caps glyphs are not available for a given font,
jdaggett@4624 4164 user agents should simulate a small-caps font, for example by taking a
jdaggett@6648 4165 normal font and replacing the glyphs for lowercase letters with scaled
jdaggett@6648 4166 versions of the glyphs for uppercase characters (replacing the glyphs for
jdaggett@6648 4167 both upper and lowercase letters in the case of ‘<a
jdaggett@4624 4168 href="#all-small-caps"><code class=property>all-small-caps</code></a>’).
jdaggett@6648 4169
jdaggett@6648 4170 <div class=figure style="padding: 0; margin: auto;"><img alt="synthetic vs.
jdaggett@6648 4171 real small-caps" class=hires src=synthetic-vs-real-small-caps.png
bert@8683 4172 width=512>
jdaggett@6648 4173 <p class=caption>Synthetic vs. real small-caps
jdaggett@6648 4174 </div>
jdaggett@6648 4175
jdaggett@6648 4176 <p>To match the surrounding text, a font may provide alternate glyphs for
jdaggett@6648 4177 caseless characters when these features are enabled but when a user agent
jdaggett@6648 4178 simulates small capitals, it must not attempt to simulate alternates for
jdaggett@6648 4179 codepoints which are considered caseless.
jdaggett@6648 4180
jdaggett@6648 4181 <div class=figure style="padding: 0; margin: auto;"><img alt="caseless
jdaggett@6648 4182 characters with small-caps, all-small-caps enabled" class=hires
bert@8683 4183 src=small-capitals-variations.png width=418>
jdaggett@6648 4184 <p class=caption>Caseless characters with small-caps, all-small-caps
jdaggett@6648 4185 enabled
jdaggett@6648 4186 </div>
jdaggett@6648 4187
jdaggett@6648 4188 <p>If either ‘<a href="#petite-caps"><code
jdaggett@4624 4189 class=property>petite-caps</code></a>’ or ‘<a
jdaggett@4624 4190 href="#all-petite-caps"><code class=property>all-petite-caps</code></a>’
jdaggett@4624 4191 is specified for a font that doesn't support these features, the property
jdaggett@4624 4192 behaves as if ‘<a href="#small-caps"><code
jdaggett@4624 4193 class=property>small-caps</code></a>’ or ‘<a
jdaggett@4624 4194 href="#all-small-caps"><code class=property>all-small-caps</code></a>’,
jdaggett@6648 4195 respectively, had been specified. If ‘<a href="#unicase"><code
jdaggett@6648 4196 class=property>unicase</code></a>’ is specified for a font that doesn't
jdaggett@6648 4197 support that feature, the property behaves as if ‘<a
jdaggett@6648 4198 href="#small-caps"><code class=property>small-caps</code></a>’ was
jdaggett@6648 4199 applied only to lowercased uppercase letters. If ‘<a
jdaggett@6648 4200 href="#titling-caps"><code class=property>titling-caps</code></a>’ is
jdaggett@6648 4201 specified with a font that does not support this feature, this property
jdaggett@6648 4202 has no visible effect. When simulated small capital glyphs are used, for
jdaggett@4624 4203 scripts that lack uppercase and lowercase letters, ‘<a
jdaggett@4624 4204 href="#small-caps"><code class=property>small-caps</code></a>’, ‘<a
jdaggett@4624 4205 href="#all-small-caps"><code class=property>all-small-caps</code></a>’,
jdaggett@4624 4206 ‘<a href="#petite-caps"><code class=property>petite-caps</code></a>’,
jdaggett@4624 4207 ‘<a href="#all-petite-caps"><code
jdaggett@4624 4208 class=property>all-petite-caps</code></a>’ and ‘<a
jdaggett@4624 4209 href="#unicase"><code class=property>unicase</code></a>’ have no visible
jdaggett@2462 4210 effect.
jdaggett@1662 4211
jdaggett@6648 4212 <p>When casing transforms are used to simulate small capitals, the casing
jdaggett@8280 4213 transformations must match those used for the <span
jdaggett@6648 4214 class=property>‘<code class=property>text-transform</code>’</span>
jdaggett@6648 4215 property.
jdaggett@6648 4216
jdaggett@6648 4217 <p>As a last resort, unscaled uppercase letter glyphs in a normal font may
jdaggett@6648 4218 replace glyphs in a small-caps font so that the text appears in all
jdaggett@6648 4219 uppercase letters.
jdaggett@6648 4220
jdaggett@6648 4221 <div class=figure style="padding: 0; margin: auto;"><img alt="using
jdaggett@6648 4222 all-small-caps in acronym-laden text" class=hires
bert@8683 4223 src=acronym-laden-text.png width=596>
jdaggett@6648 4224 <p class=caption>Using small capitals to improve readability in
jdaggett@6648 4225 acronym-laden text
jdaggett@6648 4226 </div>
jdaggett@6648 4227
jdaggett@1662 4228 <div class=example>
jdaggett@1662 4229 <p>Quotes rendered italicised, with small-caps on the first line:</p>
jdaggett@1662 4230
jdaggett@1662 4231 <pre>blockquote { font-style: italic; }
jdaggett@1662 4232 blockquote:first-line { font-variant: small-caps; }
jdaggett@1662 4233
jdaggett@8397 4234 &lt;blockquote><a href="http://lists.w3.org/Archives/Public/www-style/2009Dec/0036.html" style="text-decoration: none; border: none;">I'll be honor-bound to slap them like a haddock.</a>&lt;/blockquote>
jdaggett@1662 4235 </pre>
jdaggett@1662 4236 </div>
jdaggett@2118 4237 <!-- prop: font-variant-numeric -->
jdaggett@2118 4238
jdaggett@2118 4239 <h3 id=font-variant-numeric-prop><span class=secno>6.7 </span>Numerical
jdaggett@1662 4240 formatting: the <a
jdaggett@1662 4241 href="#propdef-font-variant-numeric">font-variant-numeric</a> property</h3>
jdaggett@1662 4242
jdaggett@5809 4243 <table class=propdef id=namefont-variant-numericvaluenormal-ltnu>
jdaggett@1662 4244 <tbody>
jdaggett@1662 4245 <tr>
jdaggett@1662 4246 <td>Name:
jdaggett@1662 4247
jdaggett@1662 4248 <td><dfn id=propdef-font-variant-numeric>font-variant-numeric</dfn>
jdaggett@1662 4249
jdaggett@1662 4250 <tr>
jdaggett@1662 4251 <td>Value:
jdaggett@1662 4252
jdaggett@8278 4253 <td><a href="#font-variant-numeric-normal-value"
jdaggett@8278 4254 title="normal!!font-variant-numeric">normal</a> | [ <a
jdaggett@8225 4255 href="#numeric-figure-values"><var>&lt;numeric-figure-values&gt;</var></a>
jdaggett@8225 4256 || <a
jdaggett@8225 4257 href="#numeric-spacing-values"><var>&lt;numeric-spacing-values&gt;</var></a>
jdaggett@8225 4258 || <a
jdaggett@8225 4259 href="#numeric-fraction-values"><var>&lt;numeric-fraction-values&gt;</var></a>
jdaggett@8225 4260 || <a href="#ordinal">ordinal</a> || <a
jdaggett@8225 4261 href="#slashed-zero">slashed-zero</a> ]
jdaggett@1662 4262
jdaggett@1662 4263 <tr>
jdaggett@1662 4264 <td>Initial:
jdaggett@1662 4265
jdaggett@1662 4266 <td>normal
jdaggett@1662 4267
jdaggett@1662 4268 <tr>
jdaggett@1662 4269 <td>Applies to:
jdaggett@1662 4270
jdaggett@1662 4271 <td>all elements
jdaggett@1662 4272
jdaggett@1662 4273 <tr>
jdaggett@1662 4274 <td>Inherited:
jdaggett@1662 4275
jdaggett@1662 4276 <td>yes
jdaggett@1662 4277
jdaggett@1662 4278 <tr>
jdaggett@1662 4279 <td>Percentages:
jdaggett@1662 4280
jdaggett@1662 4281 <td>N/A
jdaggett@1662 4282
jdaggett@1662 4283 <tr>
jdaggett@1662 4284 <td>Media:
jdaggett@1662 4285
jdaggett@1662 4286 <td>visual
jdaggett@1662 4287
jdaggett@1662 4288 <tr>
jdaggett@1662 4289 <td>Computed value:
jdaggett@1662 4290
jdaggett@1662 4291 <td>as specified
jdaggett@7377 4292
jdaggett@7377 4293 <tr>
jdaggett@7377 4294 <td>Animatable:
jdaggett@7377 4295
jdaggett@7377 4296 <td>no
jdaggett@1662 4297 </table>
jdaggett@1662 4298
jdaggett@8311 4299 <p>Specifies control over numerical forms. The example below shows how some
jdaggett@8311 4300 of these values can be combined to influence the rendering of tabular data
jdaggett@8311 4301 with fonts that support these features. Within normal paragraph text,
jdaggett@8311 4302 proportional numbers are used while tabular numbers are used so that
jdaggett@8311 4303 columns of numbers line up properly:
jdaggett@1662 4304
jdaggett@1662 4305 <div class=figure style="padding: 0; margin: auto;"><img alt="combining
jdaggett@1662 4306 number styles" src=numberstyles.png>
jdaggett@1662 4307 <p class=caption>Using number styles
jdaggett@1662 4308 </div>
jdaggett@1662 4309
jdaggett@8311 4310 <p>Possible combinations:
jdaggett@8311 4311
jdaggett@8311 4312 <pre
jdaggett@8311 4313 class=prod><dfn id=numeric-figure-values><var>&lt;numeric-figure-values&gt;</var></dfn> = [ <a href="#lining-nums">lining-nums</a> | <a href="#oldstyle-nums">oldstyle-nums</a> ]</pre>
jdaggett@8311 4314
jdaggett@8311 4315 <pre
jdaggett@8311 4316 class=prod><dfn id=numeric-spacing-values><var>&lt;numeric-spacing-values&gt;</var></dfn> = [ <a href="#proportional-nums">proportional-nums</a> | <a href="#tabular-nums">tabular-nums</a> ]</pre>
jdaggett@8311 4317
jdaggett@8311 4318 <pre
jdaggett@8311 4319 class=prod><dfn id=numeric-fraction-values><var>&lt;numeric-fraction-values&gt;</var></dfn> = [ <a href="#diagonal-fractions">diagonal-fractions</a> | <a href="#stacked-fractions">stacked-fractions</a> ]</pre>
jdaggett@8311 4320
jdaggett@8311 4321 <p>Individual values have the following meanings:
jdaggett@8311 4322
jdaggett@1662 4323 <dl>
jdaggett@8311 4324 <dt><dfn id=font-variant-numeric-normal-value
jdaggett@8311 4325 title="normal!!font-variant-numeric">normal</dfn>
jdaggett@8311 4326
jdaggett@8311 4327 <dd>None of the features listed below are enabled.
jdaggett@8311 4328
jdaggett@8311 4329 <dt><dfn id=lining-nums>lining-nums</dfn>
jdaggett@8311 4330
jdaggett@8311 4331 <dd>Enables display of lining numerals (OpenType feature: <span
jdaggett@8311 4332 class=tag>lnum</span>).
jdaggett@8311 4333
jdaggett@8311 4334 <dt><dfn id=oldstyle-nums>oldstyle-nums</dfn>
jdaggett@8311 4335
jdaggett@8311 4336 <dd>Enables display of old-style numerals (OpenType feature: <span
jdaggett@8311 4337 class=tag>onum</span>).
jdaggett@8311 4338
jdaggett@8311 4339 <dt><dfn id=proportional-nums>proportional-nums</dfn>
jdaggett@8311 4340
jdaggett@8311 4341 <dd>Enables display of proportional numerals (OpenType feature: <span
jdaggett@8311 4342 class=tag>pnum</span>).
jdaggett@8311 4343
jdaggett@8311 4344 <dt><dfn id=tabular-nums>tabular-nums</dfn>
jdaggett@8311 4345
jdaggett@8311 4346 <dd>Enables display of tabular numerals (OpenType feature: <span
jdaggett@8311 4347 class=tag>tnum</span>).
jdaggett@8311 4348
jdaggett@1662 4349 <dt><dfn id=diagonal-fractions>diagonal-fractions</dfn>
jdaggett@1662 4350
jdaggett@6436 4351 <dd>Enables display of lining diagonal fractions (OpenType feature: <span
jdaggett@6436 4352 class=tag>frac</span>).
jdaggett@1662 4353 </dl>
jdaggett@1662 4354
jdaggett@1662 4355 <div class=featex><img alt="diagonal fraction example" src=frac.png></div>
jdaggett@1662 4356
jdaggett@1662 4357 <dl>
jdaggett@1662 4358 <dt><dfn id=stacked-fractions>stacked-fractions</dfn>
jdaggett@1662 4359
jdaggett@6436 4360 <dd>Enables display of lining stacked fractions (OpenType feature: <span
jdaggett@6436 4361 class=tag>afrc</span>).
jdaggett@1662 4362 </dl>
jdaggett@1662 4363
jdaggett@1662 4364 <div class=featex><img alt="stacked fraction example" src=afrc.png></div>
jdaggett@1662 4365
jdaggett@1662 4366 <dl>
jdaggett@3638 4367 <dt><dfn id=ordinal>ordinal</dfn>
jdaggett@3638 4368
jdaggett@3638 4369 <dd>Enables display of forms used with ordinal numbers (OpenType feature:
jdaggett@6436 4370 <span class=tag>ordn</span>).
jdaggett@3638 4371
jdaggett@1662 4372 <dt><dfn id=slashed-zero>slashed-zero</dfn>
jdaggett@1662 4373
jdaggett@6436 4374 <dd>Enables display of slashed zeros (OpenType feature: <span
jdaggett@6436 4375 class=tag>zero</span>).
jdaggett@1662 4376 </dl>
jdaggett@1662 4377
jdaggett@1662 4378 <div class=featex><img alt="slashed zero example" src=zero.png></div>
jdaggett@1662 4379
jdaggett@1662 4380 <div class=example id=steak-marinade>
jdaggett@1662 4381 <p>A simple flank steak marinade recipe, rendered with automatic fractions
jdaggett@1662 4382 and old-style numerals:</p>
jdaggett@1662 4383
jdaggett@1662 4384 <pre>.amount { font-variant-numeric: oldstyle-nums diagonal-fractions; }
jdaggett@1662 4385
jdaggett@1662 4386 &lt;h4>Steak marinade:&lt;/h4>
jdaggett@1662 4387 &lt;ul>
jdaggett@1662 4388 &lt;li>&lt;span class="amount">2&lt;/span> tbsp olive oil&lt;/li>
jdaggett@1662 4389 &lt;li>&lt;span class="amount">1&lt;/span> tbsp lemon juice&lt;/li>
jdaggett@1662 4390 &lt;li>&lt;span class="amount">1&lt;/span> tbsp soy sauce&lt;/li>
jdaggett@1662 4391 &lt;li>&lt;span class="amount">1 1/2&lt;/span> tbsp dry minced onion&lt;/li>
jdaggett@1662 4392 &lt;li>&lt;span class="amount">2 1/2&lt;/span> tsp italian seasoning&lt;/li>
jdaggett@1732 4393 &lt;li>Salt &amp;amp; pepper&lt;/li>
jdaggett@1662 4394 &lt;/ul>
jdaggett@1662 4395
jdaggett@5596 4396 &lt;p>Mix the meat with the marinade and let it sit covered in the refrigerator
jdaggett@5596 4397 for a few hours or overnight.&lt;/p>
jdaggett@1662 4398 </pre>
jdaggett@8311 4399
jdaggett@8311 4400 <p>Note that the fraction feature is only applied to values not the entire
jdaggett@8311 4401 paragraph. Fonts often implement this feature using contextual rules
jdaggett@8311 4402 based on the use of the slash (‘<code class=css>/</code>’) character.
jdaggett@8311 4403 As such, it's not suitable for use as a paragraph-level style.</p>
jdaggett@1662 4404 </div>
jdaggett@2118 4405 <!-- prop: font-variant-alternates -->
jdaggett@2118 4406
jdaggett@2118 4407 <h3 id=font-variant-alternates-prop><span class=secno>6.8 </span>Alternates
jdaggett@2118 4408 and swashes: the <a
jdaggett@2118 4409 href="#propdef-font-variant-alternates">font-variant-alternates</a>
jdaggett@2118 4410 property</h3>
jdaggett@2118 4411
jdaggett@6176 4412 <table class=propdef id=namefont-variant-alternatesvaluenormal-s>
jdaggett@2118 4413 <tbody>
jdaggett@2118 4414 <tr>
jdaggett@2118 4415 <td>Name:
jdaggett@2118 4416
jdaggett@2118 4417 <td><dfn
jdaggett@2118 4418 id=propdef-font-variant-alternates>font-variant-alternates</dfn>
jdaggett@2118 4419
jdaggett@2118 4420 <tr>
jdaggett@2118 4421 <td>Value:
jdaggett@2118 4422
jdaggett@8225 4423 <td>normal | [ <a href="#stylistic"
jdaggett@8225 4424 title=stylistic>stylistic(&lt;feature-value-name&gt;)</a> || <a
jdaggett@8225 4425 href="#historical-forms">historical-forms</a> || <a href="#styleset"
jdaggett@8225 4426 title=styleset>styleset(&lt;feature-value-name&gt; #)</a> || <a
jdaggett@8225 4427 href="#character-variant"
jdaggett@8225 4428 title=character-variant>character-variant(&lt;feature-value-name&gt;
jdaggett@8225 4429 #)</a> || <a href="#swash"
jdaggett@8225 4430 title=swash>swash(&lt;feature-value-name&gt;)</a> || <a
jdaggett@8225 4431 href="#ornaments"
jdaggett@8225 4432 title=ornaments>ornaments(&lt;feature-value-name&gt;)</a> || <a
jdaggett@8225 4433 href="#annotation"
jdaggett@8225 4434 title=annotation>annotation(&lt;feature-value-name&gt;)</a> ]
jdaggett@2118 4435
jdaggett@2118 4436 <tr>
jdaggett@2118 4437 <td>Initial:
jdaggett@2118 4438
jdaggett@2118 4439 <td>normal
jdaggett@2118 4440
jdaggett@2118 4441 <tr>
jdaggett@2118 4442 <td>Applies to:
jdaggett@2118 4443
jdaggett@2118 4444 <td>all elements
jdaggett@2118 4445
jdaggett@2118 4446 <tr>
jdaggett@2118 4447 <td>Inherited:
jdaggett@2118 4448
jdaggett@2118 4449 <td>yes
jdaggett@2118 4450
jdaggett@2118 4451 <tr>
jdaggett@2118 4452 <td>Percentages:
jdaggett@2118 4453
jdaggett@2118 4454 <td>N/A
jdaggett@2118 4455
jdaggett@2118 4456 <tr>
jdaggett@2118 4457 <td>Media:
jdaggett@2118 4458
jdaggett@2118 4459 <td>visual
jdaggett@2118 4460
jdaggett@2118 4461 <tr>
jdaggett@2118 4462 <td>Computed value:
jdaggett@2118 4463
jdaggett@2118 4464 <td>as specified
jdaggett@7377 4465
jdaggett@7377 4466 <tr>
jdaggett@7377 4467 <td>Animatable:
jdaggett@7377 4468
jdaggett@7377 4469 <td>no
jdaggett@2118 4470 </table>
jdaggett@2118 4471
jdaggett@2118 4472 <p>For any given character, fonts can provide a variety of alternate glyphs
jdaggett@2118 4473 in addition to the default glyph for that character. This property
jdaggett@2118 4474 provides control over the selection of these alternate glyphs.
jdaggett@2118 4475
jdaggett@8311 4476 <p>For many of the property values listed below, several different
jdaggett@8311 4477 alternate glyphs are available. How many alternates are available and what
jdaggett@8356 4478 they represent is font-specific, so these are each marked <dfn
jdaggett@8356 4479 id=font-specific>font specific</dfn> in the value definitions below.
jdaggett@8356 4480 Because the nature of these alternates is font-specific, the <a
jdaggett@8311 4481 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8311 4482 rule is used to define values for a specific font family or set of
jdaggett@8311 4483 families that associate a font-specific numeric
jdaggett@8311 4484 <code>&lt;feature-index&gt;</code> with a custom
jdaggett@8311 4485 <code>&lt;feature-value-name&gt;</code>, which is then used in this
jdaggett@8311 4486 property to select specific alternates:
jdaggett@8311 4487
jdaggett@8311 4488 <pre>@font-feature-values Noble Script { @swash { swishy: 1; flowing: 2; } }
jdaggett@8311 4489
jdaggett@8311 4490 p {
jdaggett@8311 4491 font-family: Noble Script;
jdaggett@8311 4492 font-variant-alternates: swash(flowing); /* use swash alternate #2 */
jdaggett@8311 4493 }</pre>
jdaggett@8311 4494
jdaggett@8312 4495 <p>When a particular <code>&lt;feature-value-name&gt;</code> has not been
jdaggett@8312 4496 defined for a given family or for a particular feature type, the computed
jdaggett@8312 4497 value must be the same as if it had been defined. However, property values
jdaggett@8312 4498 that contain these undefined <code>&lt;feature-value-name&gt;</code>
jdaggett@8312 4499 identifiers must be ignored when choosing glyphs.
jdaggett@8312 4500
jdaggett@8312 4501 <pre>/* these two style rules are effectively the same */
jdaggett@8312 4502 p { font-variant-alternates: swash(unknown-value); } /* not a defined value, ignored */
jdaggett@8312 4503 p { font-variant-alternates: normal; }
jdaggett@8312 4504 </pre>
jdaggett@8312 4505
jdaggett@8312 4506 <p>This allows values to be defined and used for a given set of font
jdaggett@8312 4507 families but ignored if fallback occurs, since the font family name would
jdaggett@8312 4508 be different. If a given value is outside the range supported by a given
jdaggett@8312 4509 font, the value is ignored. These values never apply to generic font
jdaggett@8312 4510 families.
jdaggett@2556 4511
jdaggett@2118 4512 <p>Individual values have the following meanings:
jdaggett@2118 4513
jdaggett@2118 4514 <dl>
jdaggett@8278 4515 <dt><dfn id=font-variant-alternates-normal-value
jdaggett@8278 4516 title="normal!!font-variant-alternates">normal</dfn>
jdaggett@5809 4517
jdaggett@5809 4518 <dd>None of the features listed below are enabled.
jdaggett@5809 4519
jdaggett@2118 4520 <dt><dfn id=historical-forms>historical-forms</dfn>
jdaggett@2118 4521
jdaggett@6436 4522 <dd>Enables display of historical forms (OpenType feature: <span
jdaggett@6436 4523 class=tag>hist</span>).
jdaggett@2118 4524 </dl>
jdaggett@2118 4525
jdaggett@2118 4526 <div class=featex><img alt="historical form example" src=hist.png></div>
jdaggett@2118 4527
jdaggett@2118 4528 <dl>
jdaggett@8311 4529 <dt><dfn id=stylistic
jdaggett@8311 4530 title=stylistic>stylistic(&lt;feature-value-name&gt;)</dfn>
jdaggett@8311 4531
jdaggett@8356 4532 <dd>Enables display of stylistic alternates (<a
jdaggett@8356 4533 href="#font-specific"><em>font specific</em></a>, OpenType feature: <span
jdaggett@8356 4534 class=tag>salt &lt;feature-index&gt;</span>).
jdaggett@8311 4535 </dl>
jdaggett@8311 4536
jdaggett@8311 4537 <div class=featex><img alt="stylistic alternate example" src=salt.png></div>
jdaggett@8311 4538
jdaggett@8311 4539 <dl>
jdaggett@8225 4540 <dt><dfn id=styleset title=styleset>styleset(&lt;feature-value-name&gt;
jdaggett@8225 4541 #)</dfn>
jdaggett@2118 4542
jdaggett@8356 4543 <dd>Enables display with stylistic sets (<a href="#font-specific"><em>font
jdaggett@8356 4544 specific</em></a>, OpenType feature: <span
jdaggett@8356 4545 class=tag>ss&lt;feature-index&gt;</span> OpenType currently defines <span
jdaggett@8356 4546 class=tag>ss01</span> through <span class=tag>ss20</span>).
jdaggett@2118 4547 </dl>
jdaggett@2118 4548
jdaggett@2118 4549 <div class=featex><img alt="styleset example" src=ssnn.png></div>
jdaggett@2118 4550
jdaggett@2118 4551 <dl>
jdaggett@8225 4552 <dt><dfn id=character-variant
jdaggett@8225 4553 title=character-variant>character-variant(&lt;feature-value-name&gt;
jdaggett@8225 4554 #)</dfn>
jdaggett@2118 4555
jdaggett@8356 4556 <dd>Enables display of specific character variants (<a
jdaggett@8356 4557 href="#font-specific"><em>font specific</em></a>, OpenType feature: <span
jdaggett@6436 4558 class=tag>cv&lt;feature-index&gt;</span> OpenType currently defines <span
jdaggett@6436 4559 class=tag>cv01</span> through <span class=tag>cv99</span>).
jdaggett@2118 4560
jdaggett@8225 4561 <dt><dfn id=swash title=swash>swash(&lt;feature-value-name&gt;)</dfn>
jdaggett@2118 4562
jdaggett@8356 4563 <dd>Enables display of swash glyphs (<a href="#font-specific"><em>font
jdaggett@8356 4564 specific</em></a>, OpenType feature: <span class=tag>swsh
jdaggett@8356 4565 &lt;feature-index&gt;, cswh &lt;feature-index&gt;</span>).
jdaggett@2118 4566 </dl>
jdaggett@2118 4567
jdaggett@2118 4568 <div class=featex><img alt="swash example" src=swsh.png></div>
jdaggett@2118 4569
jdaggett@2118 4570 <dl>
jdaggett@8225 4571 <dt><dfn id=ornaments
jdaggett@7060 4572 title=ornaments>ornaments(&lt;feature-value-name&gt;)</dfn>
jdaggett@2118 4573
jdaggett@2118 4574 <dd>Enables replacement of default glyphs with ornaments, if provided in
jdaggett@8356 4575 the font (<a href="#font-specific"><em>font specific</em></a>, OpenType
jdaggett@8356 4576 feature: <span class=tag>ornm &lt;feature-index&gt;</span>). Some fonts
jdaggett@8356 4577 may offer ornament glyphs as alternates for a wide collection of
jdaggett@8356 4578 characters; however, displaying arbitrary characters (e.g.,
jdaggett@8356 4579 alphanumerics) as ornaments is poor practice as it distorts the semantics
jdaggett@8356 4580 of the data. Font designers are encouraged to encode all ornaments
jdaggett@8356 4581 (except those explicitly encoded in the Unicode Dingbats blocks, etc.) as
jdaggett@8356 4582 alternates for the bullet character (U+2022) to allow authors to select
jdaggett@8356 4583 the desired glyph using ‘<a href="#ornaments"><code
jdaggett@8356 4584 class=property>ornaments</code></a>’.
jdaggett@2118 4585 </dl>
jdaggett@2118 4586
jdaggett@2118 4587 <div class=featex><img alt="ornaments example" src=ornm.png></div>
jdaggett@2118 4588
jdaggett@2118 4589 <dl>
jdaggett@8225 4590 <dt><dfn id=annotation
jdaggett@7060 4591 title=annotation>annotation(&lt;feature-value-name&gt;)</dfn>
jdaggett@2118 4592
jdaggett@8356 4593 <dd>Enables display of alternate annotation forms (<a
jdaggett@8356 4594 href="#font-specific"><em>font specific</em></a>, OpenType feature: <span
jdaggett@8356 4595 class=tag>nalt &lt;feature-index&gt;</span>).
jdaggett@2118 4596 </dl>
jdaggett@2118 4597
jdaggett@2118 4598 <div class=featex><img alt="alternate annotation form example"
jdaggett@2118 4599 src=nalt.png></div>
jdaggett@2118 4600
jdaggett@2472 4601 <h3 id=font-feature-values><span class=secno>6.9 </span>Defining font
jdaggett@8311 4602 specific alternates: the <dfn id=at-font-feature-values-rule
jdaggett@8311 4603 style="font-weight: inherit; font-style:
jdaggett@8311 4604 inherit"><code>@font-feature-values</code></dfn> rule</h3>
jdaggett@2472 4605
jdaggett@4624 4606 <p>Several of the possible values of ‘<a
jdaggett@4624 4607 href="#propdef-font-variant-alternates"><code
jdaggett@4624 4608 class=property>font-variant-alternates</code></a>’ listed above are
jdaggett@8356 4609 labeled as <a href="#font-specific"><em>font specific</em></a>. For these
jdaggett@8356 4610 features fonts may define not just a single glyph but a set of alternate
jdaggett@8356 4611 glyphs with an index to select a given alternate. Since these are font
jdaggett@8356 4612 family specific, the <a
jdaggett@8311 4613 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8356 4614 rule is used to define named values for these indices for a given family.
jdaggett@8356 4615
jdaggett@8356 4616 <p class=note>See the <a href="#om-fontfeaturevalues">object model
jdaggett@8356 4617 reference section</a> for a description of the interfaces used to modify
jdaggett@8356 4618 these rules via the CSS Object Model.
jdaggett@8356 4619
jdaggett@8356 4620 <div class=example>
jdaggett@8356 4621 <p>In the case of the swash Q in the example shown above, the swash could
jdaggett@8356 4622 be specified using these style rules:</p>
jdaggett@8356 4623
jdaggett@8356 4624 <pre>
jdaggett@7041 4625
jdaggett@2472 4626 @font-feature-values Jupiter Sans {
jdaggett@7041 4627 @swash {
jdaggett@7041 4628 delicate: 1;
jdaggett@7041 4629 flowing: 2;
jdaggett@7041 4630 }
jdaggett@2472 4631 }
jdaggett@2472 4632
jdaggett@2472 4633 h2 { font-family: Jupiter Sans, sans-serif; }
jdaggett@2472 4634
jdaggett@2472 4635 /* show the second swash variant in h2 headings */
jdaggett@2472 4636 h2:first-letter { font-variant-alternates: swash(flowing); }
jdaggett@2472 4637
jdaggett@2479 4638 &lt;h2>Quick&lt;/h2></pre>
jdaggett@2472 4639
jdaggett@8356 4640 <p>When Jupiter Sans is present, the second alternate swash alternate will
jdaggett@8356 4641 be displayed. When not present, no swash character will be shown, since
jdaggett@8356 4642 the specific named value "flowing" is only defined for the Jupiter Sans
jdaggett@8356 4643 family. The @-mark indicates the name of the property value for which a
jdaggett@8356 4644 named value can be used. The name "flowing" is chosen by the author. The
jdaggett@8356 4645 index that represents each alternate is defined within a given font's
jdaggett@8356 4646 data.</p>
jdaggett@8356 4647 </div>
jdaggett@8356 4648
jdaggett@8356 4649 <h4 id=basic-syntax><span class=secno>6.9.1 </span>Basic syntax</h4>
jdaggett@8356 4650
jdaggett@8356 4651 <p>An <a
jdaggett@8356 4652 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8356 4653 rule is composed of a list of font families followed by a block containing
jdaggett@8356 4654 individual <a href="#featurevalueblock"><i
jdaggett@8356 4655 title="feature_value_block">feature value blocks</i></a> that take the
jdaggett@8356 4656 form of @-rules. Each block defines a set of named values for a specific
jdaggett@8356 4657 font feature when a given set of font families is used. Effectively, they
jdaggett@8356 4658 define a mapping of ⟨family, feature, ident⟩ → ⟨values⟩ where
jdaggett@8356 4659 ⟨values⟩ are the numeric indices used for specific features defined
jdaggett@8356 4660 for a given font.
jdaggett@8031 4661
jdaggett@8031 4662 <p>In terms of the grammar, this specification defines the following
jdaggett@8312 4663 productions:
jdaggett@8225 4664
jdaggett@8225 4665 <pre><dfn id=fontfeaturevaluesrule>font_feature_values_rule</dfn>
jdaggett@8225 4666 : <a href="#fontfeaturevaluessym"><i>FONT_FEATURE_VALUES_SYM</i></a> <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#fontfamilynamelist"><i>font_family_name_list</i></a> <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>*
jdaggett@8225 4667 '{' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#featurevalueblock"><i>feature_value_block</i></a>? [ <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#featurevalueblock"><i>feature_value_block</i></a>? ]* '}' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>*
jdaggett@8225 4668 ;
jdaggett@8225 4669
jdaggett@8225 4670 <dfn id=fontfamilynamelist>font_family_name_list</dfn>
jdaggett@8225 4671 : <a href="#fontfamilyname"><i>font_family_name</i></a> [ <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* ',' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#fontfamilyname"><i>font_family_name</i></a> ]*
jdaggett@8225 4672 ;
jdaggett@8225 4673
jdaggett@8225 4674 <dfn id=fontfamilyname>font_family_name</dfn>
jdaggett@8225 4675 : <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>STRING</i></a> | [ <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>IDENT</i></a> [ <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>IDENT</i></a> ]* ]
jdaggett@8225 4676 ;
jdaggett@8225 4677
jdaggett@8225 4678 <dfn id=featurevalueblock>feature_value_block</dfn>
jdaggett@8225 4679 : <a href="#featuretype"><i>feature_type</i></a> <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>*
jdaggett@8225 4680 '{' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#featurevaluedefinition"><i>feature_value_definition</i></a>? [ <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* ';' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="#featurevaluedefinition"><i>feature_value_definition</i></a>? ]* '}' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>*
jdaggett@8225 4681 ;
jdaggett@8225 4682
jdaggett@8225 4683 <dfn id=featuretype>feature_type</dfn>:
jdaggett@8225 4684 <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>ATKEYWORD</i></a>
jdaggett@8225 4685 ;
jdaggett@8225 4686
jdaggett@8225 4687 <dfn id=featurevaluedefinition>feature_value_definition</dfn>
jdaggett@8225 4688 : <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>IDENT</i></a> <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* ':' <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>NUMBER</i></a> [ <a href="http://www.w3.org/TR/CSS21/grammar.html#scanner"><i>S</i></a>* <a href="http://www.w3.org/TR/CSS21/syndata.html#tokenization"><i>NUMBER</i></a> ]*
jdaggett@8225 4689 ;
jdaggett@8225 4690 </pre>
jdaggett@8225 4691
jdaggett@8032 4692 <p>The following new token is introduced:
jdaggett@8032 4693
jdaggett@8225 4694 <pre>@{F}{O}{N}{T}{-}{F}{E}{A}{T}{U}{R}{E}{-}{V}{A}{L}{U}{E}{S} {return <dfn id=fontfeaturevaluessym>FONT_FEATURE_VALUES_SYM</dfn>;}
jdaggett@2118 4695 </pre>
jdaggett@2118 4696
jdaggett@8356 4697 <p><a href="#featurevalueblock"><i title="feature_value_block">Feature
jdaggett@8356 4698 value blocks</i></a> are handled as <a
jdaggett@8356 4699 href="http://www.w3.org/TR/CSS2/syndata.html#at-rules">at-rules</a>, they
jdaggett@8356 4700 consist of everything up to the next block or semi-colon, whichever comes
jdaggett@8356 4701 first.
jdaggett@8356 4702
jdaggett@8356 4703 <p>The <a href="#fontfamilynamelist"><i title="font_family_name_list">font
jdaggett@8356 4704 family list</i></a> is a comma-delimited list of <a
jdaggett@8356 4705 href="#fontfamilyname"><i title="font_family_name">font family
jdaggett@8356 4706 names</i></a> that match the definition of <a
jdaggett@8356 4707 href="#family-name-value"><var>&lt;family-name&gt;</var></a> for the <a
jdaggett@8278 4708 href="#propdef-font-family" title="font-family!!property">‘<code
jdaggett@8356 4709 class=property>font-family</code>’</a> property. This means that only
jdaggett@8356 4710 named font families are allowed, rules that include generic or system
jdaggett@8356 4711 fonts in the list of font families are syntax errors. However, if a user
jdaggett@8356 4712 agent defines a generic font to be a specific named font (e.g. Helvetica),
jdaggett@8356 4713 the settings associated with that family name will be used. If syntax
jdaggett@8356 4714 errors occur within the font family list, the entire rule must be ignored.
jdaggett@8356 4715
jdaggett@8356 4716 <p>Within <a href="#featurevalueblock"><i
jdaggett@8356 4717 title="feature_value_block">feature value blocks</i></a>, the <a
jdaggett@8356 4718 href="#featuretype"><i title="feature_type">feature type</i></a> is
jdaggett@8356 4719 ‘<code class=css>@</code>’ followed by the name of one of the <a
jdaggett@8356 4720 href="#font-specific"><em>font specific</em></a> property values of ‘<a
jdaggett@8356 4721 href="#propdef-font-variant-alternates"><code
jdaggett@8356 4722 class=property>font-variant-alternates</code></a>’ (e.g. <a
jdaggett@8356 4723 href="#swash"><code>@swash</code></a>). The identifiers used within
jdaggett@8356 4724 feature value definitions follow the rules of CSS user identifiers and are
jdaggett@8356 4725 case-sensitive. They are unique only for a given set of font families and
jdaggett@8356 4726 <a href="#featuretype"><i title="feature_type">feature type</i></a>. The
jdaggett@8356 4727 same identifier used with a different <a href="#featuretype"><i
jdaggett@8356 4728 title="feature_type">feature type</i></a> is treated as a separate and
jdaggett@8356 4729 distinct value. If the same identifier is defined mulitple times for a
jdaggett@8356 4730 given <a href="#featuretype"><i title="feature_type">feature type</i></a>
jdaggett@8356 4731 and font family, the last defined value is used. Values associated with a
jdaggett@8356 4732 given identifier are limited to integer values 0 or greater.
jdaggett@8356 4733
jdaggett@8356 4734 <p>When syntax errors occur within a <a href="#featurevaluedefinition"><i
jdaggett@8356 4735 title="feature_value_definition">feature value definition</i></a>, such as
jdaggett@8356 4736 invalid identifiers or values, the entire <a
jdaggett@8356 4737 href="#featurevaluedefinition"><i title="feature_value_definition">feature
jdaggett@8356 4738 value definition</i></a> must be omitted, just as syntax errors in style
jdaggett@8356 4739 declarations are handled. When the <a href="#featuretype"><i
jdaggett@8356 4740 title="feature_type">feature type</i></a> is invalid, the entire
jdaggett@8356 4741 associated <a href="#featurevalueblock"><i
jdaggett@8356 4742 title="feature_value_block">feature value block</i></a> must be ignored.
jdaggett@8356 4743
jdaggett@8356 4744 <div class=example>
jdaggett@8356 4745 <p>Rules that are equivalent given syntax error handling:</p>
jdaggett@8356 4746
jdaggett@8356 4747 <pre>@font-feature-values Bongo {
jdaggett@7679 4748 @swash { ornate: 1; }
jdaggett@7679 4749 annotation { boxed: 4; } /* should be @annotation! */
jdaggett@8031 4750 @swash { double-loops: 1; flowing: -1; } /* negative value */
jdaggett@8031 4751 @ornaments ; /* incomplete definition */
jdaggett@8031 4752 @styleset { double-W: 14; sharp-terminals: 16 1 } /* missing ; */
jdaggett@8356 4753 <a href="http://www.angryalien.com/0504/shiningbunnies.html" style="text-decoration: none; border: none;">redrum</a> /* random editing mistake */
jdaggett@7679 4754 }</pre>
jdaggett@7679 4755
jdaggett@8356 4756 <p>The example above is equivalent to:</p>
jdaggett@8356 4757
jdaggett@8356 4758 <pre>@font-feature-values Bongo {
jdaggett@7679 4759 @swash { ornate: 1; }
jdaggett@8031 4760 @swash { double-loops: 1; }
jdaggett@8031 4761 @styleset { double-W: 14; sharp-terminals: 16 1; }
jdaggett@7679 4762 }</pre>
jdaggett@8356 4763 </div>
jdaggett@7096 4764
jdaggett@8311 4765 <p>If multiple <a
jdaggett@8311 4766 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8356 4767 rules are defined for a given family, the resulting values definitions are
jdaggett@8356 4768 the union of the definitions contained within these rules. This allows a
jdaggett@8356 4769 set of named values to be defined for a given font family globally for a
jdaggett@8356 4770 site and specific additions made per-page.
jdaggett@8356 4771
jdaggett@8356 4772 <div class=example>
jdaggett@8356 4773 <p>Using both site-wide and per-page feature values:</p>
jdaggett@8356 4774
jdaggett@8356 4775 <pre>
jdaggett@2472 4776 site.css:
jdaggett@2472 4777
jdaggett@2472 4778 @font-feature-values Mercury Serif {
jdaggett@7041 4779 @styleset {
jdaggett@7041 4780 stacked-g: 3; /* "two-storey" versions of g, a */
jdaggett@7041 4781 stacked-a: 4;
jdaggett@7041 4782 }
jdaggett@2472 4783 }
jdaggett@2472 4784
jdaggett@2472 4785 page.css:
jdaggett@8277 4786
jdaggett@2472 4787 @font-feature-values Mercury Serif {
jdaggett@7041 4788 @styleset {
jdaggett@7041 4789 geometric-m: 7; /* alternate version of m */
jdaggett@7041 4790 }
jdaggett@2472 4791 }
jdaggett@8277 4792
jdaggett@2472 4793 body {
jdaggett@2472 4794 font-family: Mercury Serif, serif;
jdaggett@2472 4795
jdaggett@2472 4796 /* enable both the use of stacked g and alternate m */
jdaggett@2472 4797 font-variant-alternates: styleset(stacked-g, geometric-m);
jdaggett@2472 4798 }</pre>
jdaggett@8356 4799 </div>
jdaggett@8356 4800
jdaggett@8356 4801 <div class=example>
jdaggett@8356 4802 <p>Using a commonly named value allows authors to use a single style rule
jdaggett@8356 4803 to cover a set of fonts for which the underlying selector is different
jdaggett@8356 4804 for each font. If either font in the example below is found, a circled
jdaggett@8356 4805 number glyph will be used:</p>
jdaggett@8356 4806
jdaggett@8356 4807 <pre>@font-feature-values Taisho Gothic {
jdaggett@7041 4808 @annotation { boxed: 1; circled: 4; }
jdaggett@2118 4809 }
jdaggett@2118 4810
jdaggett@2118 4811 @font-feature-values Otaru Kisa {
jdaggett@7041 4812 @annotation { circled: 1; black-boxed: 3; }
jdaggett@2118 4813 }
jdaggett@2118 4814
jdaggett@2118 4815 h3.title {
jdaggett@2118 4816 /* circled form defined for both fonts */
jdaggett@2118 4817 font-family: Taisho Gothic, Otaru Kisa;
jdaggett@2118 4818 font-variant: annotation(circled);
jdaggett@2118 4819 }</pre>
jdaggett@8356 4820 </div>
jdaggett@8356 4821
jdaggett@8356 4822 <h4 id=multi-valued-feature-value-definitions><span class=secno>6.9.2
jdaggett@8356 4823 </span>Multi-valued feature value definitions</h4>
jdaggett@8356 4824
jdaggett@8356 4825 <p>Most <a href="#font-specific"><em>font specific</em></a> ‘<a
jdaggett@8356 4826 href="#propdef-font-variant-alternates"><code
jdaggett@8356 4827 class=property>font-variant-alternates</code></a>’ property values take
jdaggett@8356 4828 a single value (e.g. ‘<a href="#swash"><code
jdaggett@8356 4829 class=property>swash</code></a>’). The ‘<a
jdaggett@8356 4830 href="#character-variant"><code
jdaggett@8356 4831 class=property>character-variant</code></a>’ property value allows two
jdaggett@8356 4832 values and ‘<a href="#styleset"><code
jdaggett@8356 4833 class=property>styleset</code></a>’ allows an unlimited number.
jdaggett@3571 4834
jdaggett@3571 4835 <p>For the styleset property value, multiple values indicate the style sets
jdaggett@7095 4836 to be enabled. Values between 1 and 99 enable OpenType features <span
jdaggett@7095 4837 class=tag>ss01</span> through <span class=tag>ss99</span>. However, the
jdaggett@7095 4838 OpenType standard only officially defines <span class=tag>ss01</span>
jdaggett@8356 4839 through <span class=tag>ss20</span>. For OpenType fonts, values greater
jdaggett@8356 4840 than 99 or equal to 0 do not generate a syntax error when parsed but
jdaggett@8356 4841 enable no OpenType features.
jdaggett@2472 4842
jdaggett@2472 4843 <pre>@font-feature-values Mars Serif {
jdaggett@8277 4844 @styleset {
jdaggett@7041 4845 alt-g: 1; /* implies ss01 = 1 */
jdaggett@7041 4846 curly-quotes: 3; /* implies ss03 = 1 */
jdaggett@7041 4847 code: 4 5; /* implies ss04 = 1, ss05 = 1 */
jdaggett@7041 4848 }
jdaggett@7041 4849
jdaggett@7041 4850 @styleset {
jdaggett@7095 4851 dumb: 125; /* &gt;99, ignored */
jdaggett@7041 4852 }
jdaggett@7041 4853
jdaggett@7041 4854 @swash {
jdaggett@7041 4855 swishy: 3 5; /* more than 1 value for swash, syntax error */
jdaggett@7041 4856 }
jdaggett@2472 4857 }
jdaggett@2472 4858
jdaggett@2472 4859 p.codeblock {
jdaggett@2472 4860 /* implies ss03 = 1, ss04 = 1, ss05 = 1 */
jdaggett@2472 4861 font-variant-alternates: styleset(curly-quotes, code);
jdaggett@2472 4862 }</pre>
jdaggett@2472 4863
jdaggett@2472 4864 <p>For character-variant, a single value between 1 and 99 indicates the
jdaggett@6436 4865 enabling of OpenType feature <span class=tag>cv01</span> through <span
jdaggett@7095 4866 class=tag>cv99</span>. For OpenType fonts, values greater than 99 or equal
jdaggett@8356 4867 to 0 are ignored but do not generate a syntax error when parsed but enable
jdaggett@8356 4868 no OpenType features. When two values are listed, the first value
jdaggett@8356 4869 indicates the feature used and the second the value passed for that
jdaggett@8356 4870 feature. If more than two values are assigned to a given name, a syntax
jdaggett@8356 4871 error occurs and the entire <a href="#featurevaluedefinition"><i
jdaggett@8356 4872 title="feature_value_definition">feature value definition</i></a> is
jdaggett@8356 4873 ignored.
jdaggett@2472 4874
jdaggett@2472 4875 <pre>@font-feature-values MM Greek {
jdaggett@7041 4876 @character-variant { alpha-2: 1 2; } /* implies cv01 = 2 */
jdaggett@7041 4877 @character-variant { beta-3: 2 3; } /* implies cv02 = 3 */
jdaggett@8356 4878 @character-variant { epsilon: 5 3 6; } /* more than 2 values, syntax error, definition ignored */
jdaggett@7041 4879 @character-variant { gamma: 12; } /* implies cv12 = 1 */
jdaggett@7041 4880 @character-variant { zeta: 20 3; } /* implies cv20 = 3 */
jdaggett@7041 4881 @character-variant { zeta-2: 20 2; } /* implies cv20 = 2 */
jdaggett@7041 4882 @character-variant { silly: 105; } /* &gt;99, ignored */
jdaggett@7041 4883 @character-variant { dumb: 323 3; } /* &gt;99, ignored */
jdaggett@2472 4884 }
jdaggett@2472 4885
jdaggett@2472 4886 #title {
jdaggett@2472 4887 /* use the third alternate beta, first alternate gamma */
jdaggett@2472 4888 font-variant-alternates: character-variant(beta-3, gamma);
jdaggett@3571 4889 }
jdaggett@3571 4890
jdaggett@3571 4891 p {
jdaggett@3571 4892 /* zeta-2 follows zeta, implies cv20 = 2 */
jdaggett@3571 4893 font-variant-alternates: character-variant(zeta, zeta-2);
jdaggett@3571 4894 }
jdaggett@3571 4895
jdaggett@3571 4896 .special {
jdaggett@3571 4897 /* zeta follows zeta-2, implies cv20 = 3 */
jdaggett@3571 4898 font-variant-alternates: character-variant(zeta-2, zeta);
jdaggett@2472 4899 }</pre>
jdaggett@2472 4900
jdaggett@2472 4901 <div class=figure><img alt="Matching text on Byzantine seals using
jdaggett@2472 4902 character variants" src=byzantineseal.png>
jdaggett@2472 4903 <p class=caption>Byzantine seal text displayed with character variants
jdaggett@2472 4904 </div>
jdaggett@2472 4905
jdaggett@2472 4906 <div class=example>
jdaggett@2472 4907 <p>In the figure above, the text in red is rendered using a font
jdaggett@2472 4908 containing character variants that mimic the character forms found on a
jdaggett@2472 4909 Byzantine seal from the 8th century A.D. Two lines below is the same text
jdaggett@2472 4910 displayed in a font without variants. Note the two variants for U and N
jdaggett@2509 4911 used on the seal.</p>
jdaggett@2472 4912
jdaggett@2472 4913 <pre>@font-feature-values Athena Ruby {
jdaggett@7041 4914 @character-variant {
jdaggett@7041 4915 leo-B: 2 1;
jdaggett@7041 4916 leo-M: 13 3;
jdaggett@7041 4917 leo-alt-N: 14 1;
jdaggett@7041 4918 leo-N: 14 2;
jdaggett@8277 4919 leo-T: 20 1;
jdaggett@7041 4920 leo-U: 21 2;
jdaggett@7041 4921 leo-alt-U: 21 4;
jdaggett@7041 4922 }
jdaggett@2472 4923 }
jdaggett@2472 4924
jdaggett@2472 4925 p {
jdaggett@6653 4926 font-variant: discretionary-ligatures,
jdaggett@6653 4927 character-variant(leo-B, leo-M, leo-N, leo-T, leo-U);
jdaggett@2472 4928 }
jdaggett@2472 4929
jdaggett@8277 4930 span.alt-N {
jdaggett@2472 4931 font-variant-alternates: character-variant(leo-alt-N);
jdaggett@2472 4932 }
jdaggett@2472 4933
jdaggett@2472 4934 span.alt-U {
jdaggett@2472 4935 font-variant-alternates: character-variant(leo-alt-U);
jdaggett@2472 4936 }
jdaggett@2472 4937
jdaggett@2472 4938 &lt;p>ENO....UP͞RSTU&lt;span class="alt-U">U&lt;/span>͞&lt;span class="alt-U">U&lt;/span>ΚΑΙTỤẠG̣IUPNS&lt;/p>
jdaggett@2472 4939
jdaggett@8277 4940 &lt;p>LEON|ΚΑΙCONSTA|NTI&lt;span class="alt-N">N&lt;/span>OS..|STOIBAṢ.|LIṢROM|AIO&lt;span class="alt-N">N&lt;/span>&lt;/p>
jdaggett@2472 4941 </pre>
jdaggett@2118 4942 </div>
jdaggett@2118 4943
jdaggett@2118 4944 <h3 id=font-variant-east-asian-prop><span class=secno>6.10 </span>East
jdaggett@2118 4945 Asian text rendering: the <a
jdaggett@1662 4946 href="#propdef-font-variant-east-asian">font-variant-east-asian</a>
jdaggett@1662 4947 property</h3>
jdaggett@1662 4948
jdaggett@5809 4949 <table class=propdef id=namefont-variant-east-asianvaluenormal-l>
jdaggett@1662 4950 <tbody>
jdaggett@1662 4951 <tr>
jdaggett@1662 4952 <td>Name:
jdaggett@1662 4953
jdaggett@1662 4954 <td><dfn
jdaggett@1662 4955 id=propdef-font-variant-east-asian>font-variant-east-asian</dfn>
jdaggett@1662 4956
jdaggett@1662 4957 <tr>
jdaggett@1662 4958 <td>Value:
jdaggett@1662 4959
jdaggett@8278 4960 <td><a href="#font-variant-east-asian-normal-value"
jdaggett@8278 4961 title="normal!!font-variant-east-asian">normal</a> | [ <a
jdaggett@8225 4962 href="#east-asian-variant-values"><var>&lt;east-asian-variant-values&gt;</var></a>
jdaggett@8225 4963 || <a
jdaggett@8225 4964 href="#east-asian-width-values"><var>&lt;east-asian-width-values&gt;</var></a>
jdaggett@8225 4965 || <a href="#ruby">ruby</a> ]
jdaggett@1662 4966
jdaggett@1662 4967 <tr>
jdaggett@1662 4968 <td>Initial:
jdaggett@1662 4969
jdaggett@1662 4970 <td>normal
jdaggett@1662 4971
jdaggett@1662 4972 <tr>
jdaggett@1662 4973 <td>Applies to:
jdaggett@1662 4974
jdaggett@1662 4975 <td>all elements
jdaggett@1662 4976
jdaggett@1662 4977 <tr>
jdaggett@1662 4978 <td>Inherited:
jdaggett@1662 4979
jdaggett@1662 4980 <td>yes
jdaggett@1662 4981
jdaggett@1662 4982 <tr>
jdaggett@1662 4983 <td>Percentages:
jdaggett@1662 4984
jdaggett@1662 4985 <td>N/A
jdaggett@1662 4986
jdaggett@1662 4987 <tr>
jdaggett@1662 4988 <td>Media:
jdaggett@1662 4989
jdaggett@1662 4990 <td>visual
jdaggett@1662 4991
jdaggett@1662 4992 <tr>
jdaggett@1662 4993 <td>Computed value:
jdaggett@1662 4994
jdaggett@1662 4995 <td>as specified
jdaggett@7377 4996
jdaggett@7377 4997 <tr>
jdaggett@7377 4998 <td>Animatable:
jdaggett@7377 4999
jdaggett@7377 5000 <td>no
jdaggett@1662 5001 </table>
jdaggett@1662 5002
jdaggett@6693 5003 <p>Allows control of glyph substitution and sizing in East Asian text.
jdaggett@1662 5004
jdaggett@1662 5005 <pre
jdaggett@8225 5006 class=prod><dfn id=east-asian-variant-values><var>&lt;east-asian-variant-values&gt;</var></dfn> = [ <a href="#jis78">jis78</a> | <a href="#jis83">jis83</a> | <a href="#jis90">jis90</a> | <a href="#jis04">jis04</a> | <a href="#simplified">simplified</a> | <a href="#traditional">traditional</a> ]</pre>
jdaggett@1662 5007
jdaggett@1662 5008 <pre
jdaggett@8225 5009 class=prod><dfn id=east-asian-width-values><var>&lt;east-asian-width-values&gt;</var></dfn> = [ <a href="#full-width">full-width</a> | <a href="#proportional-width">proportional-width</a> ]</pre>
jdaggett@1732 5010
jdaggett@1732 5011 <p>Individual values have the following meanings:
jdaggett@1662 5012
jdaggett@1662 5013 <dl>
jdaggett@8278 5014 <dt><dfn id=font-variant-east-asian-normal-value
jdaggett@8278 5015 title="normal!!font-variant-east-asian">normal</dfn>
jdaggett@5809 5016
jdaggett@5809 5017 <dd>None of the features listed below are enabled.
jdaggett@5809 5018
jdaggett@1662 5019 <dt><dfn id=jis78>jis78</dfn>
jdaggett@1662 5020
jdaggett@6436 5021 <dd>Enables rendering of JIS78 forms (OpenType feature: <span
jdaggett@6436 5022 class=tag>jp78</span>).
jdaggett@1662 5023 </dl>
jdaggett@1662 5024
jdaggett@1662 5025 <div class=featex><img alt="JIS78 form example" src=jp78.png></div>
jdaggett@1662 5026
jdaggett@1662 5027 <dl>
jdaggett@1662 5028 <dt><dfn id=jis83>jis83</dfn>
jdaggett@1662 5029
jdaggett@6436 5030 <dd>Enables rendering of JIS83 forms (OpenType feature: <span
jdaggett@6436 5031 class=tag>jp83</span>).
jdaggett@1662 5032
jdaggett@1662 5033 <dt><dfn id=jis90>jis90</dfn>
jdaggett@1662 5034
jdaggett@6436 5035 <dd>Enables rendering of JIS90 forms (OpenType feature: <span
jdaggett@6436 5036 class=tag>jp90</span>).
jdaggett@1662 5037
jdaggett@1662 5038 <dt><dfn id=jis04>jis04</dfn>
jdaggett@1662 5039
jdaggett@6436 5040 <dd>Enables rendering of JIS2004 forms (OpenType feature: <span
jdaggett@6436 5041 class=tag>jp04</span>).
jdaggett@6693 5042 <p>The various JIS variants reflect the glyph forms defined in different
jdaggett@6693 5043 Japanese national standards. Fonts generally include glyphs defined by
jdaggett@6693 5044 the most recent national standard but it's sometimes necessary to use
jdaggett@6693 5045 older variants, to match signage for example.</p>
jdaggett@1662 5046
jdaggett@2504 5047 <dt><dfn id=simplified>simplified</dfn>
jdaggett@2504 5048
jdaggett@6436 5049 <dd>Enables rendering of simplified forms (OpenType feature: <span
jdaggett@6436 5050 class=tag>smpl</span>).
jdaggett@2504 5051
jdaggett@2504 5052 <dt><dfn id=traditional>traditional</dfn>
jdaggett@2504 5053
jdaggett@6436 5054 <dd>Enables rendering of traditional forms (OpenType feature: <span
jdaggett@6436 5055 class=tag>trad</span>).
jdaggett@1662 5056 </dl>
jdaggett@1662 5057
jdaggett@8312 5058 <p>The ‘<a href="#simplified"><code
jdaggett@8312 5059 class=property>simplified</code></a>’ and ‘<a
jdaggett@8312 5060 href="#traditional"><code class=property>traditional</code></a>’ values
jdaggett@8312 5061 allow control over the glyph forms for characters which have been
jdaggett@8312 5062 simplified over time but for which the older, traditional form is still
jdaggett@8312 5063 used in some contexts. The exact set of characters and glyph forms will
jdaggett@8312 5064 vary to some degree by context for which a given font was designed.
jdaggett@8312 5065
jdaggett@1662 5066 <div class=featex><img alt="tradtional form example" src=trad.png></div>
jdaggett@1662 5067
jdaggett@1662 5068 <dl>
jdaggett@1662 5069 <dt><dfn id=full-width>full-width</dfn>
jdaggett@1662 5070
jdaggett@6436 5071 <dd>Enables rendering of full-width variants (OpenType feature: <span
jdaggett@6436 5072 class=tag>fwid</span>).
jdaggett@1662 5073
jdaggett@1662 5074 <dt><dfn id=proportional-width>proportional-width</dfn>
jdaggett@1662 5075
jdaggett@1662 5076 <dd>Enables rendering of proportionally-spaced variants (OpenType feature:
jdaggett@6436 5077 <span class=tag>pwid</span>).
jdaggett@1662 5078 </dl>
jdaggett@1662 5079
jdaggett@1662 5080 <div class=featex><img alt="proportionally spaced Japanese example"
jdaggett@1662 5081 src=pwid.png></div>
jdaggett@1662 5082
jdaggett@3638 5083 <dl>
jdaggett@3638 5084 <dt><dfn id=ruby>ruby</dfn>
jdaggett@3638 5085
jdaggett@6436 5086 <dd>Enables display of ruby variant glyphs (OpenType feature: <span
jdaggett@6436 5087 class=tag>ruby</span>). Since ruby text is generally smaller than the
jdaggett@3638 5088 associated body text, font designers can design special glyphs for use
jdaggett@3638 5089 with ruby that are more readable than scaled down versions of the default
jdaggett@3638 5090 glyphs. Only glyph selection is affected, there is no associated font
jdaggett@3638 5091 scaling or other change that affects line layout. The red ruby text below
jdaggett@3638 5092 is shown with default glyphs (top) and with ruby variant glyphs (bottom).
jdaggett@3638 5093 Note the slight difference in stroke thickness.
jdaggett@3638 5094 </dl>
jdaggett@3638 5095
jdaggett@3638 5096 <div class=featex><img alt="ruby variant example" src=rubyshinkansen.png></div>
jdaggett@3638 5097
jdaggett@2118 5098 <h3 id=font-variant-prop><span class=secno>6.11 </span>Overall shorthand
jdaggett@1856 5099 for font rendering: the <a href="#propdef-font-variant">font-variant</a>
jdaggett@1662 5100 property</h3>
jdaggett@1662 5101
jdaggett@6436 5102 <table class=propdef id=namefont-variantvaluenormal-none-ltcommo>
jdaggett@1662 5103 <tbody>
jdaggett@1662 5104 <tr>
jdaggett@1662 5105 <td>Name:
jdaggett@1662 5106
jdaggett@8278 5107 <td><dfn id=propdef-font-variant
jdaggett@8278 5108 title="font-variant!!property">font-variant</dfn>
jdaggett@1662 5109
jdaggett@1662 5110 <tr>
jdaggett@1662 5111 <td>Value:
jdaggett@1662 5112
jdaggett@8278 5113 <td><a href="#font-variant-normal-value"
jdaggett@8278 5114 title="normal!!font-variant">normal</a> | <a
jdaggett@8278 5115 href="#font-variant-none-value" title="none!!font-variant">none</a> | [
jdaggett@8278 5116 <a href="#common-lig-values"><var>&lt;common-lig-values&gt;</var></a>
jdaggett@8278 5117 || <a
jdaggett@8225 5118 href="#discretionary-lig-values"><var>&lt;discretionary-lig-values&gt;</var></a>
jdaggett@8225 5119 || <a
jdaggett@8225 5120 href="#historical-lig-values"><var>&lt;historical-lig-values&gt;</var></a>
jdaggett@8225 5121 || <a
jdaggett@8225 5122 href="#contextual-alt-values"><var>&lt;contextual-alt-values&gt;</var></a>
jdaggett@8225 5123 || <a href="#stylistic"><var
jdaggett@8225 5124 title=stylistic>stylistic(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 5125 href="#historical-forms"><var>historical-forms</var></a> || <a
jdaggett@8225 5126 href="#styleset"><var
jdaggett@8225 5127 title=styleset>styleset(&lt;feature-value-name&gt; #)</var></a> || <a
jdaggett@8225 5128 href="#character-variant"><var
jdaggett@8225 5129 title=character-variant>character-variant(&lt;feature-value-name&gt;
jdaggett@8225 5130 #)</var></a> || <a href="#swash"><var
jdaggett@8225 5131 title=swash>swash(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 5132 href="#ornaments"><var
jdaggett@8225 5133 title=ornaments>ornaments(&lt;feature-value-name&gt;)</var></a> || <a
jdaggett@8225 5134 href="#annotation"><var
jdaggett@8225 5135 title=annotation>annotation(&lt;feature-value-name&gt;)</var></a> || [
jdaggett@8225 5136 <a href="#small-caps"><i>small-caps</i></a> | <a
jdaggett@8225 5137 href="#all-small-caps"><i>all-small-caps</i></a> | <a
jdaggett@8225 5138 href="#petite-caps"><i>petite-caps</i></a> | <a
jdaggett@8225 5139 href="#all-petite-caps"><i>all-petite-caps</i></a> | <a
jdaggett@8225 5140 href="#unicase"><i>unicase</i></a> | <a
jdaggett@8225 5141 href="#titling-caps"><i>titling-caps</i></a> ] || <a
jdaggett@8225 5142 href="#numeric-figure-values"><var>&lt;numeric-figure-values&gt;</var></a>
jdaggett@8225 5143 || <a
jdaggett@8225 5144 href="#numeric-spacing-values"><var>&lt;numeric-spacing-values&gt;</var></a>
jdaggett@8225 5145 || <a
jdaggett@8225 5146 href="#numeric-fraction-values"><var>&lt;numeric-fraction-values&gt;</var></a>
jdaggett@8225 5147 || <a href="#ordinal"><i>ordinal</i></a> || <a
jdaggett@8225 5148 href="#slashed-zero"><i>slashed-zero</i></a> || <a
jdaggett@8225 5149 href="#east-asian-variant-values"><var>&lt;east-asian-variant-values&gt;</var></a>
jdaggett@8225 5150 || <a
jdaggett@8225 5151 href="#east-asian-width-values"><var>&lt;east-asian-width-values&gt;</var></a>
jdaggett@8225 5152 || <a href="#ruby"><i>ruby</i></a> ]
jdaggett@1662 5153
jdaggett@1662 5154 <tr>
jdaggett@1662 5155 <td>Initial:
jdaggett@1662 5156
jdaggett@1662 5157 <td>normal
jdaggett@1662 5158
jdaggett@1662 5159 <tr>
jdaggett@1662 5160 <td>Applies to:
jdaggett@1662 5161
jdaggett@1662 5162 <td>all elements
jdaggett@1662 5163
jdaggett@1662 5164 <tr>
jdaggett@1662 5165 <td>Inherited:
jdaggett@1662 5166
jdaggett@1662 5167 <td>yes
jdaggett@1662 5168
jdaggett@1662 5169 <tr>
jdaggett@1662 5170 <td>Percentages:
jdaggett@1662 5171
jdaggett@7377 5172 <td>see individual properties
jdaggett@1662 5173
jdaggett@1662 5174 <tr>
jdaggett@1662 5175 <td>Media:
jdaggett@1662 5176
jdaggett@1662 5177 <td>visual
jdaggett@1662 5178
jdaggett@1662 5179 <tr>
jdaggett@1662 5180 <td>Computed value:
jdaggett@1662 5181
jdaggett@7377 5182 <td>see individual properties
jdaggett@7377 5183
jdaggett@7377 5184 <tr>
jdaggett@7377 5185 <td>Animatable:
jdaggett@7377 5186
jdaggett@7377 5187 <td>see individual properties
jdaggett@1662 5188 </table>
jdaggett@1662 5189
jdaggett@8313 5190 <p>The <a href="#propdef-font-variant"
jdaggett@8313 5191 title="font-variant!!property">‘<code
jdaggett@8313 5192 class=property>font-variant</code>’</a> property is a shorthand for all
jdaggett@8313 5193 font-variant subproperties. The value <dfn id=font-variant-normal-value
jdaggett@8313 5194 title="normal!!font-variant">‘<code
jdaggett@8313 5195 class=property>normal</code>’</dfn> resets all subproperties of <a
jdaggett@8313 5196 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8313 5197 class=property>font-variant</code>’</a> to their inital value. The <dfn
jdaggett@8313 5198 id=font-variant-none-value title="none!!font-variant">‘<code
jdaggett@8313 5199 class=property>none</code>’</dfn> value sets ‘<a
jdaggett@8313 5200 href="#propdef-font-variant-ligatures"><code
jdaggett@8278 5201 class=property>font-variant-ligatures</code></a>’ to ‘<code
jdaggett@8278 5202 class=property>none</code>’ and resets all other font feature properties
jdaggett@8278 5203 to their initial value. Like other shorthands, using <a
jdaggett@8278 5204 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8313 5205 class=property>font-variant</code>’</a> resets unspecified <a
jdaggett@8313 5206 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8313 5207 class=property>font-variant</code>’</a> subproperties to their initial
jdaggett@8313 5208 values. It does not reset the values of either ‘<a
jdaggett@8313 5209 href="#propdef-font-language-override"><code
jdaggett@8279 5210 class=property>font-language-override</code></a>’ or <a
jdaggett@8279 5211 href="#propdef-font-feature-settings"
jdaggett@8279 5212 title="font-feature-settings!!property">‘<code
jdaggett@8279 5213 class=property>font-feature-settings</code>’</a>.
jdaggett@1662 5214
jdaggett@2118 5215 <h3 id=font-feature-settings-prop><span class=secno>6.12 </span>Low-level
jdaggett@2509 5216 font feature settings control: the <a
jdaggett@1662 5217 href="#propdef-font-feature-settings">font-feature-settings</a> property</h3>
jdaggett@1662 5218
jdaggett@4624 5219 <table class=propdef id=namefont-feature-settingsvaluenormal-ltf>
jdaggett@1662 5220 <tbody>
jdaggett@1662 5221 <tr>
jdaggett@1662 5222 <td>Name:
jdaggett@1662 5223
jdaggett@8279 5224 <td><dfn id=propdef-font-feature-settings
jdaggett@8279 5225 title="font-feature-settings!!property">font-feature-settings</dfn>
jdaggett@1662 5226
jdaggett@1662 5227 <tr>
jdaggett@1662 5228 <td>Value:
jdaggett@1662 5229
jdaggett@8278 5230 <td><a href="#font-feature-settings-normal-value"
jdaggett@8278 5231 title="normal!!font-feature-settings">normal</a> | <a
jdaggett@8225 5232 href="#feature-tag-value"><var>&lt;feature-tag-value&gt;</var></a> #
jdaggett@1662 5233
jdaggett@1662 5234 <tr>
jdaggett@1662 5235 <td>Initial:
jdaggett@1662 5236
jdaggett@1662 5237 <td>normal
jdaggett@1662 5238
jdaggett@1662 5239 <tr>
jdaggett@1662 5240 <td>Applies to:
jdaggett@1662 5241
jdaggett@1662 5242 <td>all elements
jdaggett@1662 5243
jdaggett@1662 5244 <tr>
jdaggett@1662 5245 <td>Inherited:
jdaggett@1662 5246
jdaggett@1662 5247 <td>yes
jdaggett@1662 5248
jdaggett@1662 5249 <tr>
jdaggett@1662 5250 <td>Percentages:
jdaggett@1662 5251
jdaggett@1662 5252 <td>N/A
jdaggett@1662 5253
jdaggett@1662 5254 <tr>
jdaggett@1662 5255 <td>Media:
jdaggett@1662 5256
jdaggett@1662 5257 <td>visual
jdaggett@1662 5258
jdaggett@1662 5259 <tr>
jdaggett@1662 5260 <td>Computed value:
jdaggett@1662 5261
jdaggett@1662 5262 <td>as specified
jdaggett@7377 5263
jdaggett@7377 5264 <tr>
jdaggett@7377 5265 <td>Animatable:
jdaggett@7377 5266
jdaggett@7377 5267 <td>no
jdaggett@1662 5268 </table>
jdaggett@2474 5269
jdaggett@2474 5270 <p>This property provides low-level control over OpenType font features. It
jdaggett@2474 5271 is intended as a way of providing access to font features that are not
jdaggett@8312 5272 widely used but are needed for a particular use case.
jdaggett@8312 5273
jdaggett@8312 5274 <p>Authors should generally use <a href="#propdef-font-variant"
jdaggett@8312 5275 title="font-variant!!property">‘<code
jdaggett@8312 5276 class=property>font-variant</code>’</a> and its related subproperties
jdaggett@8312 5277 whenever possible and only use this property for special cases where its
jdaggett@8312 5278 use is the only way of accessing a particular infrequently used font
jdaggett@8312 5279 feature.
jdaggett@8312 5280
jdaggett@8312 5281 <pre>/* enable small caps and use second swash alternate */
jdaggett@8312 5282 font-feature-settings: "smcp", "swsh" 2;</pre>
jdaggett@8312 5283
jdaggett@8312 5284 <p>A value of <dfn id=font-feature-settings-normal-value
jdaggett@8278 5285 title="normal!!font-feature-settings">‘<code
jdaggett@8278 5286 class=property>normal</code>’</dfn> means that no change in glyph
jdaggett@8278 5287 selection or positioning occurs due to this property.
jdaggett@2474 5288
jdaggett@2509 5289 <p>Feature tag values have the following syntax:
jdaggett@2474 5290
jdaggett@2474 5291 <pre
jdaggett@8225 5292 class=prod><dfn id=feature-tag-value><var>&lt;feature-tag-value&gt;</var></dfn> = &lt;string&gt; [ &lt;integer&gt; | on | off ]?</pre>
jdaggett@2509 5293
jdaggett@5532 5294 <p>The &lt;string&gt; is a case-sensitive OpenType feature tag. As
jdaggett@5532 5295 specified in the OpenType specification, feature tags contain four ASCII
jdaggett@5532 5296 characters. Tag strings longer or shorter than four characters, or
jdaggett@5596 5297 containing characters outside the U+20–7E codepoint range are invalid.
jdaggett@8312 5298 Feature tags need only match a feature tag defined in the font, so they
jdaggett@8312 5299 are not limited to explicitly registered OpenType features. Fonts defining
jdaggett@8312 5300 custom feature tags should follow the <a
jdaggett@2474 5301 href="http://www.microsoft.com/typography/otspec/featuretags.htm">tag name
jdaggett@2474 5302 rules</a> defined in the OpenType specification <a
jdaggett@1662 5303 href="#OPENTYPE-FEATURES"
jdaggett@2474 5304 rel=biblioentry>[OPENTYPE-FEATURES]<!--{{!OPENTYPE-FEATURES}}--></a>.
jdaggett@2474 5305 Feature tags not present in the font are ignored; a user agent must not
jdaggett@2474 5306 attempt to synthesize fallback behavior based on these feature tags.
jdaggett@2474 5307
jdaggett@6436 5308 <p>This means that explicitly disabling the <span class=tag>kern</span>
jdaggett@6436 5309 feature will not affect the application of kerning data found in the
jdaggett@6436 5310 ‘<code class=property>kern</code>’ table (as opposed to kerning data
jdaggett@6436 5311 associated with the <span class=tag>kern</span> feature in the ‘<code
jdaggett@5946 5312 class=property>GPOS</code>’ table). Authors should use the ‘<a
jdaggett@5946 5313 href="#propdef-font-kerning"><code
jdaggett@5946 5314 class=property>font-kerning</code></a>’ property to explictly enable or
jdaggett@5946 5315 disable kerning since this property affects both types of kerning.
jdaggett@5946 5316
jdaggett@2509 5317 <p>If present, a value indicates an index used for glyph selection. An
jdaggett@2509 5318 &lt;integer&gt; value must be 0 or greater. A value of 0 indicates that
jdaggett@2509 5319 the feature is disabled. For boolean features, a value of 1 enables the
jdaggett@2509 5320 feature. For non-boolean features, a value of 1 or greater enables the
jdaggett@2509 5321 feature and indicates the feature selection index. A value of ‘<code
jdaggett@2509 5322 class=property>on</code>’ is synonymous with 1 and ‘<code
jdaggett@2509 5323 class=property>off</code>’ is synonymous with 0. If the value is
jdaggett@2509 5324 omitted, a value of 1 is assumed.
jdaggett@2474 5325
jdaggett@2474 5326 <pre>
jdaggett@2509 5327 font-feature-settings: "dlig" 1; /* dlig=1 enable discretionary ligatures */
jdaggett@2509 5328 font-feature-settings: "smcp" on; /* smcp=1 enable small caps */
jdaggett@2515 5329 font-feature-settings: 'c2sc'; /* c2sc=1 enable caps to small caps */
jdaggett@2509 5330 font-feature-settings: "liga" off; /* liga=0 no common ligatures */
jdaggett@2515 5331 font-feature-settings: "tnum", 'hist'; /* tnum=1, hist=1 enable tabular numbers and historical forms */
jdaggett@5530 5332 font-feature-settings: "tnum" "hist"; /* invalid, need a comma-delimited list */
jdaggett@5530 5333 font-feature-settings: "palin" off; /* good idea but invalid tagname */
jdaggett@2509 5334 font-feature-settings: "PKRN"; /* PKRN=1 enable custom feature */
jdaggett@5530 5335 font-feature-settings: dlig; /* invalid, tag must be a string */
jdaggett@2474 5336 </pre>
jdaggett@1662 5337
jdaggett@8272 5338 <p>When values greater than the range supported by the font are specified,
jdaggett@8272 5339 the behavior is explicitly undefined. For boolean features, in general
jdaggett@8272 5340 these will enable the feature. For non-boolean features, out of range
jdaggett@8272 5341 values will in general be equivalent to a 0 value. However, in both cases
jdaggett@8272 5342 the exact behavior will depend upon the way the font is designed
jdaggett@8272 5343 (specifically, which type of lookup is used to define the feature).
jdaggett@8272 5344
jdaggett@2474 5345 <p>Although specifically defined for OpenType feature tags, feature tags
jdaggett@2474 5346 for other modern font formats that support font features may be added in
jdaggett@5530 5347 the future. Where possible, features defined for other font formats should
jdaggett@5530 5348 attempt to follow the pattern of registered OpenType tags.
jdaggett@2509 5349
jdaggett@1662 5350 <div class=example>
jdaggett@1662 5351 <p>The Japanese text below will be rendered with half-width kana
jdaggett@1662 5352 characters:</p>
jdaggett@1662 5353
jdaggett@1662 5354 <pre lang=ja>
jdaggett@2509 5355 body { font-feature-settings: "hwid"; /* Half-width OpenType feature */ }
jdaggett@1662 5356
jdaggett@1662 5357 &lt;p>毎日<a href="http://images.google.com/images?q=%E3%82%AB%E3%83%AC%E3%83%BC" style="text-decoration: none;">カレー</a>食べてるのに、飽きない&lt;/p>
jdaggett@1662 5358 </pre>
jdaggett@1662 5359 </div>
jdaggett@1662 5360
jdaggett@2118 5361 <h3 id=font-language-override-prop><span class=secno>6.13 </span>Font
jdaggett@1732 5362 language override: the <a
jdaggett@1732 5363 href="#propdef-font-language-override">font-language-override</a> property</h3>
jdaggett@1732 5364
jdaggett@5809 5365 <table class=propdef id=namefont-language-overridevaluenormal-lt>
jdaggett@1662 5366 <tbody>
jdaggett@1662 5367 <tr>
jdaggett@1662 5368 <td>Name:
jdaggett@1662 5369
jdaggett@1732 5370 <td><dfn id=propdef-font-language-override>font-language-override</dfn>
jdaggett@1662 5371
jdaggett@1662 5372 <tr>
jdaggett@1662 5373 <td>Value:
jdaggett@1662 5374
jdaggett@8278 5375 <td><a href="#font-language-override-normal-value"
jdaggett@8278 5376 title="normal!!font-language-override">normal</a> | <a
jdaggett@8278 5377 href="#font-language-override-string-value"><var>&lt;string&gt;</var></a>
jdaggett@1662 5378
jdaggett@1662 5379 <tr>
jdaggett@1662 5380 <td>Initial:
jdaggett@1662 5381
jdaggett@8278 5382 <td><a href="#font-language-override-normal-value"
jdaggett@8278 5383 title="normal!!font-language-override">normal</a>
jdaggett@1662 5384
jdaggett@1662 5385 <tr>
jdaggett@1662 5386 <td>Applies to:
jdaggett@1662 5387
jdaggett@1662 5388 <td>all elements
jdaggett@1662 5389
jdaggett@1662 5390 <tr>
jdaggett@1662 5391 <td>Inherited:
jdaggett@1662 5392
jdaggett@1662 5393 <td>yes
jdaggett@1662 5394
jdaggett@1662 5395 <tr>
jdaggett@1662 5396 <td>Percentages:
jdaggett@1662 5397
jdaggett@1662 5398 <td>N/A
jdaggett@1662 5399
jdaggett@1662 5400 <tr>
jdaggett@1662 5401 <td>Media:
jdaggett@1662 5402
jdaggett@1662 5403 <td>visual
jdaggett@1662 5404
jdaggett@1662 5405 <tr>
jdaggett@1662 5406 <td>Computed value:
jdaggett@1662 5407
jdaggett@1662 5408 <td>as specified
jdaggett@7377 5409
jdaggett@7377 5410 <tr>
jdaggett@7377 5411 <td>Animatable:
jdaggett@7377 5412
jdaggett@7377 5413 <td>no
jdaggett@1662 5414 </table>
jdaggett@1662 5415
jdaggett@8278 5416 <p>Normally, authors can control the use of language-specific glyph
jdaggett@8278 5417 substitutions and positioning by setting the content language of an
jdaggett@8278 5418 element, as <a href="#language-specific-support">described above</a>:
jdaggett@8278 5419
jdaggett@8278 5420 <pre>&lt;!-- Display text using S'gaw Karen specific features -->
jdaggett@8387 5421 &lt;p lang="ksw">...&lt;/p></pre>
jdaggett@8278 5422
jdaggett@8278 5423 <p>In some cases, authors may need to specify a language system that
jdaggett@8278 5424 differs from the content language, for example due to the need to mimic
jdaggett@8278 5425 another language's typographic traditions. The ‘<a
jdaggett@8278 5426 href="#propdef-font-language-override"><code
jdaggett@8278 5427 class=property>font-language-override</code></a>’ property allows
jdaggett@8278 5428 authors to explicitly specify the language system of the font, overriding
jdaggett@8278 5429 the language system implied by the content language.
jdaggett@8278 5430
jdaggett@8278 5431 <p>Values have the following meanings:
jdaggett@8278 5432
jdaggett@8278 5433 <dl>
jdaggett@8278 5434 <dt><dfn id=font-language-override-normal-value
jdaggett@8278 5435 title="normal!!font-language-override">normal</dfn>
jdaggett@8278 5436
jdaggett@8278 5437 <dd>specifies that when rendering with OpenType fonts, the content
jdaggett@8278 5438 language of the element is used to infer the OpenType language system
jdaggett@8278 5439
jdaggett@8278 5440 <dt><dfn
jdaggett@8278 5441 id=font-language-override-string-value><var>&lt;string&gt;</var></dfn>
jdaggett@8278 5442
jdaggett@8368 5443 <dd>single three-letter case-sensitive OpenType <a
jdaggett@8278 5444 href="http://www.microsoft.com/typography/otspec/languagetags.htm">language
jdaggett@8278 5445 system tag</a>, specifies the OpenType language system to be used instead
jdaggett@8278 5446 of the language system implied by the language of the element
jdaggett@8278 5447 </dl>
jdaggett@8385 5448 <!-- For this level, string represents a single language code, there's no concept of "fallback"
jdaggett@8385 5449 http://www.w3.org/2013/06/07-css-minutes.html#item04 -->
jdaggett@1662 5450
jdaggett@8312 5451 <p>Use of invalid OpenType language system tags must not generate a parse
jdaggett@8312 5452 error but must be ignored when doing glyph selection and placement.
jdaggett@8312 5453
jdaggett@1662 5454 <div class=example>
jdaggett@7179 5455 <p>The <a href="http://www.un.org/en/documents/udhr/index.shtml">Universal
jdaggett@1662 5456 Declaration of Human Rights</a> has been translated into a wide variety
jdaggett@1662 5457 of languages. In Turkish, Article 9 of this document might be marked up
jdaggett@1662 5458 as below:</p>
jdaggett@1662 5459
jdaggett@1662 5460 <pre lang=tr>&lt;body lang="tr">
jdaggett@1662 5461
jdaggett@1662 5462 &lt;h4>Madde 9&lt;/h4>
jdaggett@1662 5463 &lt;p>Hiç kimse keyfi olarak tutuklanamaz, alıkonulanamaz veya sürülemez.&lt;/p>
jdaggett@1662 5464 </pre>
jdaggett@1662 5465
jdaggett@1662 5466 <p>Here the user agent uses the value of the ‘<code
jdaggett@1662 5467 class=property>lang</code>’ attribute when rendering text and
jdaggett@1662 5468 appropriately renders this text without ‘<code
jdaggett@4624 5469 class=property>fi</code>’ ligatures. There is no need to use the ‘<a
jdaggett@4624 5470 href="#propdef-font-language-override"><code
jdaggett@4624 5471 class=property>font-language-override</code></a>’ property.</p>
jdaggett@1662 5472
jdaggett@1662 5473 <p>However, a given font may lack support for a specific language. In this
jdaggett@1662 5474 situation authors may need to use the typographic conventions of a
jdaggett@1662 5475 related language that are supported by that font:</p>
jdaggett@1662 5476
jdaggett@1662 5477 <pre lang=mk>&lt;body lang="mk"> &lt;!-- Macedonian lang code --&gt;
jdaggett@1662 5478
jdaggett@1732 5479 body { font-language-override: "SRB"; /* Serbian OpenType language tag */ }
jdaggett@1662 5480
jdaggett@1662 5481 &lt;h4>Члeн 9&lt;/h4>
jdaggett@1662 5482 &lt;p>Никoj чoвeк нeмa дa бидe пoдлoжeн нa прoизвoлнo aпсeњe, притвoр или прoгoнувaњe.&lt;/p>
jdaggett@1662 5483
jdaggett@1662 5484 </pre>
jdaggett@1662 5485
jdaggett@1662 5486 <p>The Macedonian text here will be rendered using Serbian typographic
jdaggett@1662 5487 conventions, with the assumption that the font specified supports
jdaggett@1662 5488 Serbian.</p>
jdaggett@1662 5489 </div>
jdaggett@1662 5490
jdaggett@6176 5491 <p><a id=rendering-considerations></a>
jdaggett@6176 5492
jdaggett@6699 5493 <h2 id=font-feature-resolution><span class=secno>7 </span>Font Feature
jdaggett@6699 5494 Resolution</h2>
jdaggett@6176 5495
jdaggett@6176 5496 <p>As described in the previous section, font features can be enabled in a
jdaggett@8278 5497 variety of ways, either via the use of <a href="#propdef-font-variant"
jdaggett@8278 5498 title="font-variant!!property">‘<code
jdaggett@8279 5499 class=property>font-variant</code>’</a> or <a
jdaggett@8279 5500 href="#propdef-font-feature-settings"
jdaggett@8279 5501 title="font-feature-settings!!property">‘<code
jdaggett@8279 5502 class=property>font-feature-settings</code>’</a> in a style rule or
jdaggett@8311 5503 within an <a href="#at-font-face-rule"><code>@font-face</code></a> rule.
jdaggett@8311 5504 The resolution order for the union of these settings is defined below.
jdaggett@8311 5505 Features defined via CSS properties are applied on top of layout engine
jdaggett@8311 5506 default features.
jdaggett@6176 5507
jdaggett@6699 5508 <h3 id=default-features><span class=secno>7.1 </span>Default features</h3>
jdaggett@6699 5509
jdaggett@6176 5510 <p>For OpenType fonts, user agents must enable the default features defined
jdaggett@6436 5511 in the OpenType documentation for a given script and writing mode.
jdaggett@6436 5512 Required ligatures, common ligatures and contextual forms must be enabled
jdaggett@6436 5513 by default (OpenType features: <span class=tag>rlig, liga, clig,
jdaggett@6436 5514 calt</span>), along with localized forms (OpenType feature: <span
jdaggett@6436 5515 class=tag>locl</span>), and features required for proper display of
jdaggett@6436 5516 composed characters and marks (OpenType features: <span class=tag>ccmp,
jdaggett@6436 5517 mark, mkmk</span>). These features must always be enabled, even when the
jdaggett@8278 5518 value of the <a href="#propdef-font-variant"
jdaggett@8278 5519 title="font-variant!!property">‘<code
jdaggett@8279 5520 class=property>font-variant</code>’</a> and <a
jdaggett@8279 5521 href="#propdef-font-feature-settings"
jdaggett@8279 5522 title="font-feature-settings!!property">‘<code
jdaggett@8368 5523 class=property>font-feature-settings</code>’</a> properties is <span
jdaggett@8368 5524 title="normal value">‘<code class=property>normal</code>’</span>.
jdaggett@8368 5525 Individual features are only disabled when explicitly overridden by the
jdaggett@8368 5526 author, as when ‘<a href="#propdef-font-variant-ligatures"><code
jdaggett@6176 5527 class=property>font-variant-ligatures</code></a>’ is set to ‘<a
jdaggett@6176 5528 href="#no-common-ligatures"><code
jdaggett@7377 5529 class=property>no-common-ligatures</code></a>’. For handling complex
jdaggett@7377 5530 scripts such as <a
jdaggett@6176 5531 href="http://www.microsoft.com/typography/otfntdev/arabicot/features.aspx">Arabic</a>,
jdaggett@6176 5532 <a
jdaggett@6176 5533 href="http://www.microsoft.com/typography/otfntdev/mongolot/features.htm">Mongolian</a>
jdaggett@6176 5534 or <a
jdaggett@6176 5535 href="http://www.microsoft.com/typography/otfntdev/devanot/features.aspx">Devanagari</a>
jdaggett@6436 5536 additional features are required. For upright text within vertical text
jdaggett@6436 5537 runs, vertical alternates (OpenType feature: <span class=tag>vert</span>)
jdaggett@6436 5538 must be enabled.
jdaggett@1662 5539
jdaggett@6699 5540 <h3 id=feature-precedence><span class=secno>7.2 </span>Feature precedence</h3>
jdaggett@6699 5541
jdaggett@8356 5542 <p>General and <a href="#font-specific"><em>font specific</em></a> font
jdaggett@8356 5543 feature property settings are resolved in the order below, in ascending
jdaggett@8360 5544 order of precedence. This ordering is used to construct a combined list of
jdaggett@8356 5545 font features that affect a given text run.
jdaggett@1662 5546
jdaggett@1662 5547 <ol>
jdaggett@6436 5548 <li>Font features enabled by default, including features required for a
jdaggett@6436 5549 given script.
jdaggett@6176 5550
jdaggett@8311 5551 <li>If the font is defined via an <a
jdaggett@8311 5552 href="#at-font-face-rule"><code>@font-face</code></a> rule, the font
jdaggett@8311 5553 features implied by the font-variant descriptor in the <a
jdaggett@8311 5554 href="#at-font-face-rule"><code>@font-face</code></a> rule.
jdaggett@8311 5555
jdaggett@8311 5556 <li>If the font is defined via an <a
jdaggett@8311 5557 href="#at-font-face-rule"><code>@font-face</code></a> rule, the font
jdaggett@8311 5558 features implied by the font-feature-settings descriptor in the <a
jdaggett@8311 5559 href="#at-font-face-rule"><code>@font-face</code></a> rule.
jdaggett@1662 5560
jdaggett@8278 5561 <li>Feature settings determined by properties other than <a
jdaggett@8278 5562 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8279 5563 class=property>font-variant</code>’</a> or <a
jdaggett@8279 5564 href="#propdef-font-feature-settings"
jdaggett@8279 5565 title="font-feature-settings!!property">‘<code
jdaggett@8279 5566 class=property>font-feature-settings</code>’</a>. For example, setting
jdaggett@8279 5567 a non-default value for the ‘<code
jdaggett@8360 5568 class=property>letter-spacing</code>’ property disables common
jdaggett@8360 5569 ligatures.
jdaggett@6176 5570
jdaggett@8278 5571 <li>Font features implied by the value of the <a
jdaggett@8278 5572 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8313 5573 class=property>font-variant</code>’</a> property, the related <a
jdaggett@8313 5574 href="#propdef-font-variant" title="font-variant!!property">‘<code
jdaggett@8313 5575 class=property>font-variant</code>’</a> subproperties and any other CSS
jdaggett@8360 5576 property that uses OpenType features (e.g. the ‘<a
jdaggett@8313 5577 href="#propdef-font-kerning"><code
jdaggett@4624 5578 class=property>font-kerning</code></a>’ property).
jdaggett@4624 5579
jdaggett@8279 5580 <li>Font features implied by the value of <a
jdaggett@8279 5581 href="#propdef-font-feature-settings"
jdaggett@8279 5582 title="font-feature-settings!!property">‘<code
jdaggett@8279 5583 class=property>font-feature-settings</code>’</a> property.
jdaggett@1662 5584 </ol>
jdaggett@1662 5585
jdaggett@3511 5586 <p>This ordering allows authors to set up a general set of defaults for
jdaggett@8311 5587 fonts within their <a
jdaggett@8311 5588 href="#at-font-face-rule"><code>@font-face</code></a> rules, then override
jdaggett@8311 5589 them with property settings for specific elements. General property
jdaggett@8311 5590 settings override the settings in <a
jdaggett@8311 5591 href="#at-font-face-rule"><code>@font-face</code></a> rules and low-level
jdaggett@8311 5592 font feature settings override <a href="#propdef-font-variant"
jdaggett@8278 5593 title="font-variant!!property">‘<code
jdaggett@8278 5594 class=property>font-variant</code>’</a> property settings.
jdaggett@1732 5595
jdaggett@1732 5596 <p>For situations where the combined list of font feature settings contains
jdaggett@3511 5597 more than one value for the same feature, the last value is used. When a
jdaggett@3511 5598 font lacks support for a given underlying font feature, text is simply
jdaggett@3511 5599 rendered as if that font feature was not enabled; font fallback does not
jdaggett@3511 5600 occur and no attempt is made to synthesize the feature except where
jdaggett@8360 5601 explicitly defined for specific properties.
jdaggett@1662 5602
jdaggett@6699 5603 <h3 id=feature-precedence-examples><span class=secno>7.3 </span>Feature
jdaggett@6699 5604 precedence examples</h3>
jdaggett@6699 5605
jdaggett@1662 5606 <div class=example>
jdaggett@1662 5607 <p>With the styles below, numbers are rendered proportionally when used
jdaggett@1662 5608 within a paragraph but are shown in tabular form within tables of prices:</p>
jdaggett@1662 5609
jdaggett@8277 5610 <pre>body {
jdaggett@8277 5611 font-variant-numeric: proportional-nums;
jdaggett@1662 5612 }
jdaggett@1662 5613
jdaggett@1662 5614 table.prices td {
jdaggett@8277 5615 font-variant-numeric: tabular-nums;
jdaggett@1662 5616 }
jdaggett@1662 5617 </pre>
jdaggett@1662 5618 </div>
jdaggett@1662 5619
jdaggett@1662 5620 <div class=example>
jdaggett@8360 5621 <p>When the <a href="#descdef-font-variant"
jdaggett@8360 5622 title="font-variant!!descriptor">font-variant</a> descriptor is used
jdaggett@8360 5623 within an <a href="#at-font-face-rule"><code>@font-face</code></a> rule,
jdaggett@8360 5624 it only applies to the font defined by that rule.</p>
jdaggett@1662 5625
jdaggett@1662 5626 <pre>@font-face {
jdaggett@1662 5627 font-family: MainText;
jdaggett@2556 5628 src: url(http://example.com/font.ttf);
jdaggett@1662 5629 font-variant: oldstyle-nums proportional-nums styleset(1,3);
jdaggett@1662 5630 }
jdaggett@1662 5631
jdaggett@1662 5632 body {
jdaggett@1662 5633 font-family: MainText, Helvetica;
jdaggett@1662 5634 }
jdaggett@1662 5635
jdaggett@1662 5636 table.prices td {
jdaggett@8277 5637 font-variant-numeric: tabular-nums;
jdaggett@1662 5638 }
jdaggett@1662 5639 </pre>
jdaggett@1662 5640
jdaggett@1662 5641 <p>In this case, old-style numerals will be used throughout but only where
jdaggett@1662 5642 the font "MainText" is used. Just as in the previous example, tabular
jdaggett@4624 5643 values will be used in price tables since ‘<a
jdaggett@4624 5644 href="#tabular-nums"><code class=property>tabular-nums</code></a>’
jdaggett@4624 5645 appears in a general style rule and its use is mutually exclusive with
jdaggett@4624 5646 ‘<a href="#proportional-nums"><code
jdaggett@4624 5647 class=property>proportional-nums</code></a>’. Stylistic alternate sets
jdaggett@4624 5648 will only be used where MainText is used.</p>
jdaggett@1662 5649 </div>
jdaggett@1662 5650
jdaggett@1662 5651 <div class=example>
jdaggett@8311 5652 <p>The <a href="#at-font-face-rule"><code>@font-face</code></a> rule can
jdaggett@8311 5653 also be used to access font features in locally available fonts via the
jdaggett@8311 5654 use of <code>local()</code> in the ‘<a href="#descdef-src"><code
jdaggett@8311 5655 class=property>src</code></a>’ descriptor of the <a
jdaggett@8311 5656 href="#at-font-face-rule"><code>@font-face</code></a> definition:</p>
jdaggett@1662 5657
jdaggett@1662 5658 <pre>@font-face {
jdaggett@1662 5659 font-family: BodyText;
jdaggett@1662 5660 src: local("HiraMaruPro-W4");
jdaggett@1662 5661 font-variant: proportional-width;
jdaggett@2509 5662 font-feature-settings: "ital"; /* Latin italics within CJK text feature */
jdaggett@1662 5663 }
jdaggett@1662 5664
jdaggett@1662 5665 body { font-family: BodyText, serif; }
jdaggett@1662 5666 </pre>
jdaggett@1662 5667
jdaggett@1662 5668 <p>If available, a Japanese font "Hiragino Maru Gothic" will be used. When
jdaggett@1662 5669 text rendering occurs, Japanese kana will be proportionally spaced and
jdaggett@1662 5670 Latin text will be italicised. Text rendered with the fallback serif font
jdaggett@1662 5671 will use default rendering properties.</p>
jdaggett@1662 5672 </div>
jdaggett@1662 5673
jdaggett@1662 5674 <div class=example>
jdaggett@3460 5675 <p>In the example below, discretionary ligatures are enabled only for a
jdaggett@1662 5676 downloadable font but are disabled within spans of class "special":</p>
jdaggett@1662 5677
jdaggett@1662 5678 <pre>@font-face {
jdaggett@1662 5679 font-family: main;
jdaggett@1662 5680 src: url(fonts/ffmeta.woff) format("woff");
jdaggett@3460 5681 font-variant: discretionary-ligatures;
jdaggett@1662 5682 }
jdaggett@1662 5683
jdaggett@1662 5684 body { font-family: main, Helvetica; }
jdaggett@3460 5685 span.special { font-variant-ligatures: no-discretionary-ligatures; }
jdaggett@1662 5686 </pre>
jdaggett@1662 5687
jdaggett@8360 5688 <p>Suppose one adds a rule using ‘<code
jdaggett@8360 5689 class=property>font-feature-settings</code>’ to enable discretionary
jdaggett@8360 5690 ligatures:</p>
jdaggett@1662 5691
jdaggett@1662 5692 <pre>body { font-family: main, Helvetica; }
jdaggett@2509 5693 span { font-feature-settings: "dlig"; }
jdaggett@3460 5694 span.special { font-variant-ligatures: no-discretionary-ligatures; }
jdaggett@1662 5695 </pre>
jdaggett@1662 5696
jdaggett@8360 5697 <p>In this case, discretionary ligatures <em>will</em> be rendered within
jdaggett@8360 5698 spans of class "special". This is because both the <a
jdaggett@8279 5699 href="#propdef-font-feature-settings"
jdaggett@8279 5700 title="font-feature-settings!!property">‘<code
jdaggett@8279 5701 class=property>font-feature-settings</code>’</a> and ‘<a
jdaggett@4624 5702 href="#propdef-font-variant-ligatures"><code
jdaggett@4624 5703 class=property>font-variant-ligatures</code></a>’ properties apply to
jdaggett@4624 5704 these spans. Although the ‘<code class=css>no-discretionary
jdaggett@4624 5705 ligatures</code>’ setting of ‘<a
jdaggett@4624 5706 href="#propdef-font-variant-ligatures"><code
jdaggett@4624 5707 class=property>font-variant-ligatures</code></a>’ effectively disables
jdaggett@8279 5708 the OpenType <span class=tag>dlig</span> feature, because the <a
jdaggett@8279 5709 href="#propdef-font-feature-settings"
jdaggett@8279 5710 title="font-feature-settings!!property">‘<code
jdaggett@8279 5711 class=property>font-feature-settings</code>’</a> is resolved after
jdaggett@8279 5712 that, the ‘<code class=property>dlig</code>’ value reenables
jdaggett@4624 5713 discretionary ligatures.</p>
jdaggett@1662 5714 </div>
jdaggett@1244 5715
jdaggett@7021 5716 <h2 id=object-model><span class=secno>8 </span>Object Model</h2>
jdaggett@7021 5717
jdaggett@8311 5718 <p>The contents of <a href="#at-font-face-rule"><code>@font-face</code></a>
jdaggett@8311 5719 and <a
jdaggett@8311 5720 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8311 5721 rules can be accessed via the following extensions to the CSS Object
jdaggett@8311 5722 Model.
jdaggett@7021 5723
jdaggett@7021 5724 <h3 id=om-fontface><span class=secno>8.1 </span>The <a
jdaggett@7021 5725 href="#cssfontfacerule"><code>CSSFontFaceRule</code></a> interface</h3>
jdaggett@7021 5726
jdaggett@7021 5727 <p>The <dfn id=cssfontfacerule>CSSFontFaceRule</dfn> interface represents a
jdaggett@8311 5728 <a href="#at-font-face-rule"><code>@font-face</code></a> rule.
jdaggett@7021 5729
jdaggett@7021 5730 <pre class=idl>
jdaggett@7021 5731 interface CSSFontFaceRule : CSSRule {
jdaggett@7041 5732 attribute DOMString family;
jdaggett@7041 5733 attribute DOMString src;
jdaggett@7041 5734 attribute DOMString style;
jdaggett@7041 5735 attribute DOMString weight;
jdaggett@7041 5736 attribute DOMString stretch;
jdaggett@7041 5737 attribute DOMString unicodeRange;
jdaggett@7041 5738 attribute DOMString variant;
jdaggett@7041 5739 attribute DOMString featureSettings;
jdaggett@7021 5740 }</pre>
jdaggett@7021 5741
jdaggett@7022 5742 <p>The DOM Level 2 Style specification <a href="#DOM-LEVEL-2-STYLE"
jdaggett@7022 5743 rel=biblioentry>[DOM-LEVEL-2-STYLE]<!--{{DOM-LEVEL-2-STYLE}}--></a>
jdaggett@7022 5744 defined a different variant of this rule. This definition supercedes that
jdaggett@7022 5745 one.
jdaggett@7021 5746
jdaggett@7021 5747 <h3 id=om-fontfeaturevalues><span class=secno>8.2 </span>The <a
jdaggett@7021 5748 href="#cssfontfeaturevaluesrule"><code>CSSFontFeatureValuesRule</code></a>
jdaggett@7021 5749 interface</h3>
jdaggett@7021 5750
jdaggett@7021 5751 <p>The <code>CSSRule</code> interface is extended as follows:
jdaggett@7021 5752
jdaggett@7021 5753 <pre class=idl>partial interface CSSRule {
jdaggett@7021 5754 const unsigned short FONT_FEATURE_VALUES_RULE = 14;
jdaggett@7021 5755 }</pre>
jdaggett@7021 5756
jdaggett@7021 5757 <p>The <dfn id=cssfontfeaturevaluesrule>CSSFontFeatureValuesRule</dfn>
jdaggett@8311 5758 interface represents a <a
jdaggett@8311 5759 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8311 5760 rule.
jdaggett@7021 5761
jdaggett@7021 5762 <pre class=idl>interface CSSFontFeatureValuesRule : CSSRule {
jdaggett@8640 5763 attribute DOMString fontFamily;
jdaggett@8640 5764 readonly attribute CSSFontFeatureValuesMap annotation;
jdaggett@8640 5765 readonly attribute CSSFontFeatureValuesMap ornaments;
jdaggett@8640 5766 readonly attribute CSSFontFeatureValuesMap stylistic;
jdaggett@8640 5767 readonly attribute CSSFontFeatureValuesMap swash;
jdaggett@8640 5768 readonly attribute CSSFontFeatureValuesMap characterVariant;
jdaggett@8640 5769 readonly attribute CSSFontFeatureValuesMap styleset;
jdaggett@8640 5770 }
jdaggett@8640 5771
jdaggett@8640 5772 [MapClass(DOMString, sequence&lt;unsigned long&gt;)]
jdaggett@8640 5773 interface CSSFontFeatureValuesMap {
jdaggett@8646 5774 void set(DOMString featureValueName,
jdaggett@8646 5775 (unsigned long or sequence&lt;unsigned long&gt;) values);
jdaggett@8640 5776 }</pre>
jdaggett@7021 5777
jdaggett@7021 5778 <dl class=idl-attributes>
jdaggett@8640 5779 <dt><var>fontFamily</var> of type <code>DOMString</code>
jdaggett@7021 5780
jdaggett@7021 5781 <dd>The list of one or more font families for which a given set of feature
jdaggett@7021 5782 values is defined.
jdaggett@7021 5783
jdaggett@8640 5784 <dt>value maps of type <code>CSSFontFeatureValuesMap</code>, readonly
jdaggett@8640 5785
jdaggett@8640 5786 <dd>Maps of feature values associated with feature value names for a given
jdaggett@8640 5787 ‘<a href="#propdef-font-variant-alternates"><code
jdaggett@8640 5788 class=property>font-variant-alternates</code></a>’ value type
jdaggett@7021 5789 </dl>
jdaggett@7021 5790
jdaggett@8640 5791 <p>Each value map attribute of <a
jdaggett@8640 5792 href="#cssfontfeaturevaluesrule"><code>CSSFontFeatureValuesRule</code></a>
jdaggett@8640 5793 reflects the values defined via a corresponding <a
jdaggett@8640 5794 href="#featurevalueblock"><i title="feature_value_block">feature value
jdaggett@8640 5795 block</i></a>. Thus, the <var title="annotation
jdaggett@8640 5796 attribute">annotation</var> attribute contains the values contained within
jdaggett@8640 5797 a <code title="@annotation">@annotation</code> <a
jdaggett@8640 5798 href="#featurevalueblock"><i title="feature_value_block">feature value
jdaggett@8640 5799 block</i></a>, the <var title="ornaments attribute">ornaments</var>
jdaggett@8640 5800 attribute contains the values contained with a <code
jdaggett@8640 5801 title="@ornaments">@ornaments</code> <a href="#featurevalueblock"><i
jdaggett@8640 5802 title="feature_value_block">feature value block</i></a> and so forth.
jdaggett@8640 5803
jdaggett@8654 5804 <p>The <code>CSSFontFeatureValuesMap</code> interface uses the <a
jdaggett@8655 5805 href="http://dev.w3.org/2006/webapi/WebIDL/#es-map-members">default map
jdaggett@8655 5806 class methods</a> but the <code>set</code> method has different behavior.
jdaggett@8655 5807 It takes a sequence of unsigned integers and associates it with a given
jdaggett@8654 5808 <code>featureValueName</code>. The method behaves the same as the default
jdaggett@8654 5809 map class method except that a single unsigned long value is treated as a
jdaggett@8654 5810 sequence of a single value. The method throws an exception if an invalid
jdaggett@8654 5811 number of values is passed in. If the associated <a
jdaggett@8654 5812 href="#featurevalueblock"><i title="feature_value_block">feature value
jdaggett@8640 5813 block</i></a> only allows a limited number of values, the <code>set</code>
jdaggett@8640 5814 method throws an <code>InvalidAccessError</code> exception when the input
jdaggett@8653 5815 sequence to <code>set</code> contains more than the limited number of
jdaggett@8653 5816 values. See the description of <a
jdaggett@8640 5817 href="#multi-valued-feature-value-definitions">multi-valued feature value
jdaggett@8640 5818 definitions</a> for details on the maximum number of values allowed for a
jdaggett@8640 5819 given type of <a href="#featurevalueblock"><i
jdaggett@8646 5820 title="feature_value_block">feature value block</i></a>. The
jdaggett@8653 5821 <code>get</code> method always returns a sequence of values, even if the
jdaggett@8653 5822 sequence only contains a single value.
jdaggett@8279 5823
jdaggett@2737 5824 <h2 class=no-num id=platform-props-to-css>Appendix A: Mapping platform font
jdaggett@1662 5825 properties to CSS properties</h2>
jdaggett@1662 5826
jdaggett@1662 5827 <p><em>This appendix is included as background for some of the problems and
jdaggett@890 5828 situations that are described in other sections. It should be viewed as
jdaggett@890 5829 informative only.</em>
jdaggett@890 5830
jdaggett@512 5831 <p>Font properties in CSS are designed to be independent of the underlying
jdaggett@512 5832 font formats used; they can be used to specify bitmap fonts, Type1 fonts,
jdaggett@890 5833 SVG fonts in addition to the common TrueType and OpenType fonts. But there
jdaggett@1244 5834 are facets of the TrueType and OpenType formats that often cause confusion
jdaggett@2556 5835 for authors and present challenges to implementers on different platforms.
jdaggett@1244 5836
jdaggett@1244 5837 <p>Originally developed at Apple, TrueType was designed as an outline font
jdaggett@1244 5838 format for both screen and print. Microsoft joined Apple in developing the
jdaggett@1244 5839 TrueType format and both platforms have supported TrueType fonts since
jdaggett@1244 5840 then. Font data in the TrueType format consists of a set of tables
jdaggett@1244 5841 distinguished with common four-letter tag names, each containing a
jdaggett@1244 5842 specific type of data. For example, naming information, including
jdaggett@1244 5843 copyright and license information, is stored in the ‘<code
jdaggett@7311 5844 class=property>name</code>’ table. The <a
jdaggett@7311 5845 href="#character-map"><em>character map</em></a> (‘<code
jdaggett@1244 5846 class=property>cmap</code>’) table contains a mapping of character
jdaggett@1244 5847 encodings to glyphs. Apple later added additional tables for supporting
jdaggett@1244 5848 enhanced typographic functionality; these are now called Apple Advanced
jdaggett@1244 5849 Typography, or AAT, fonts. Microsoft and Adobe developed a separate set of
jdaggett@1662 5850 tables for advanced typography and called their format OpenType <a
jdaggett@1662 5851 href="#OPENTYPE" rel=biblioentry>[OPENTYPE]<!--{{!OPENTYPE}}--></a>.
jdaggett@890 5852
jdaggett@890 5853 <p>In many cases the font data used under Microsoft Windows or Linux is
jdaggett@890 5854 slightly different from the data used under Apple's Mac OS X because the
jdaggett@6694 5855 TrueType format allowed for explicit variation across platforms. This
jdaggett@7311 5856 includes font metrics, names and <a href="#character-map"><em>character
jdaggett@7311 5857 map</em></a> data.
jdaggett@6694 5858
jdaggett@6694 5859 <p>Specifically, font family name data is handled differently across
jdaggett@6694 5860 platforms. For TrueType and OpenType fonts these names are contained in
jdaggett@6694 5861 the ‘<code class=property>name</code>’ table, in name records with
jdaggett@8276 5862 name ID 1. Mulitple names can be stored for different locales, but
jdaggett@6694 5863 Microsoft recommends fonts always include at least a US English version of
jdaggett@6694 5864 the name. On Windows, Microsoft made the decision for backwards
jdaggett@6694 5865 compatibility to limit this family name to a maximum of four faces; for
jdaggett@6694 5866 larger groupings the "preferred family" (name ID 16) or "WWS family" (name
jdaggett@6694 5867 ID 21) can be used. Other platforms such as OSX don't have this
jdaggett@8276 5868 limitation, so the family name is used to define all possible groupings.
jdaggett@6694 5869
jdaggett@6694 5870 <p>Other name table data provides names used to uniquely identify a
jdaggett@6694 5871 specific face within a family. The full font name (name ID 4) and the
jdaggett@8276 5872 Postscript name (name ID 6) describe a single face uniquely. For example,
jdaggett@8276 5873 the bold face of the Gill Sans family has a fullname of "Gill Sans Bold"
jdaggett@8276 5874 and a Postscript name of "GillSans-Bold". There can be multiple localized
jdaggett@8276 5875 versions of the fullname for a given face, but the Postscript name is
jdaggett@1244 5876 always a unique name made from a limited set of ASCII characters.
jdaggett@1244 5877
jdaggett@1244 5878 <p>On various platforms, different names are used to search for a font. For
jdaggett@1244 5879 example, with the Windows GDI CreateIndirectFont API, either a family or
jdaggett@8276 5880 fullname can be used to lookup a face, while on Mac OS X the
jdaggett@8095 5881 CTFontCreateWithName API call is used to lookup a given face using the
jdaggett@8095 5882 fullname and Postscript name. Under Linux, the fontconfig API allows fonts
jdaggett@8095 5883 to be searched using any of these names. In situations where platform
jdaggett@8095 5884 API's automatically substitute other font choices, it may be necessary to
jdaggett@8095 5885 verify a returned font matches a given name.
jdaggett@1244 5886
jdaggett@1244 5887 <p>The weight of a given face can be determined via the usWeightClass field
jdaggett@1244 5888 of the OS/2 table or inferred from the style name (name ID 2). Likewise,
jdaggett@1244 5889 the width can be determined via the usWidthClass of the OS/2 table or
jdaggett@6694 5890 inferred from the style name. For historical reasons related to synthetic
jdaggett@6694 5891 bolding at weights 200 or lower with the Windows GDI API, font designers
jdaggett@6694 5892 have sometimes skewed values in the OS/2 table to avoid these weights.
jdaggett@1244 5893
jdaggett@1244 5894 <p>Rendering complex scripts that use contextual shaping such as Thai,
jdaggett@1244 5895 Arabic and Devanagari requires features present only in OpenType or AAT
jdaggett@1244 5896 fonts. Currently, complex script rendering is supported on Windows and
jdaggett@7521 5897 Linux using OpenType font features while both OpenType and AAT font
jdaggett@7521 5898 features are used under Mac OS X.
jdaggett@1244 5899
jdaggett@2472 5900 <h2 class=no-num id=ch-ch-ch-changes>Changes</h2>
jdaggett@2472 5901
jdaggett@2472 5902 <h3 class=no-num id=recent-changes> Changes from the <a
jdaggett@8699 5903 href="http://www.w3.org/TR/2013/WD-css-fonts-3-20130711/">July 2013 CSS3
jdaggett@8699 5904 Fonts Last Call Working Draft</a></h3>
jdaggett@2472 5905
jdaggett@2472 5906 <p>Major changes include:
jdaggett@2472 5907
jdaggett@2472 5908 <ul>
jdaggett@8699 5909 <li>
jdaggett@2472 5910 </ul>
jdaggett@2472 5911
jdaggett@529 5912 <h2 class=no-num id=acknowledgments>Acknowledgments</h2>
jdaggett@529 5913
jdaggett@1662 5914 <p>I'd like to thank Tal Leming, Jonathan Kew and Christopher Slye for all
jdaggett@1662 5915 their help and feedback. John Hudson was kind enough to take the time to
jdaggett@2472 5916 explain the subtleties of OpenType language tags and provided the example
jdaggett@2472 5917 of character variant usage for displaying text on Byzantine seals. Ken
jdaggett@2472 5918 Lunde and Eric Muller provided valuable feedback on CJK OpenType features
jdaggett@2472 5919 and Unicode variation selectors. The idea for supporting font features by
jdaggett@8313 5920 using <a href="#propdef-font-variant"
jdaggett@8313 5921 title="font-variant!!property">‘<code
jdaggett@8313 5922 class=property>font-variant</code>’</a> subproperties originated with
jdaggett@8313 5923 Håkon Wium Lie, Adam Twardoch and Tal Leming. Elika Etemad supplied some
jdaggett@8313 5924 of the initial design ideas for the <a
jdaggett@8311 5925 href="#at-font-feature-values-rule"><code>@font-feature-values</code></a>
jdaggett@8311 5926 rule. Thanks also to House Industries for allowing the use of Ed Interlock
jdaggett@8311 5927 in the discretionary ligatures example.
jdaggett@1662 5928
jdaggett@529 5929 <p>A special thanks to Robert Bringhurst for the sublime mind expansion
jdaggett@529 5930 that is <em>The Elements of Typographic Style</em>.
jdaggett@529 5931
jdaggett@7242 5932 <h2 class=no-num id=conformance> Conformance</h2>
jdaggett@7242 5933
jdaggett@7242 5934 <h3 class=no-num id=conventions> Document Conventions</h3>
jdaggett@7242 5935
jdaggett@7242 5936 <p>Conformance requirements are expressed with a combination of descriptive
jdaggett@7242 5937 assertions and RFC 2119 terminology. The key words “MUST”, “MUST
jdaggett@7242 5938 NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”,
jdaggett@7242 5939 “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in the
jdaggett@7242 5940 normative parts of this document are to be interpreted as described in RFC
jdaggett@7242 5941 2119. However, for readability, these words do not appear in all uppercase
jdaggett@7242 5942 letters in this specification.
jdaggett@7242 5943
jdaggett@7242 5944 <p>All of the text of this specification is normative except sections
jdaggett@7242 5945 explicitly marked as non-normative, examples, and notes. <a
jdaggett@7242 5946 href="#RFC2119" rel=biblioentry>[RFC2119]<!--{{!RFC2119}}--></a>
jdaggett@7242 5947
jdaggett@7242 5948 <p>Examples in this specification are introduced with the words “for
jdaggett@7242 5949 example” or are set apart from the normative text with
jdaggett@7242 5950 <code>class="example"</code>, like this:
jdaggett@7242 5951
jdaggett@7242 5952 <div class=example>
jdaggett@7242 5953 <p>This is an example of an informative example.
jdaggett@7242 5954 </div>
jdaggett@7242 5955
jdaggett@7242 5956 <p>Informative notes begin with the word “Note” and are set apart from
jdaggett@7242 5957 the normative text with <code>class="note"</code>, like this:
jdaggett@7242 5958
jdaggett@7242 5959 <p class=note>Note, this is an informative note.
jdaggett@7242 5960
jdaggett@7242 5961 <h3 class=no-num id=conformance-classes> Conformance Classes</h3>
jdaggett@7242 5962
jdaggett@7242 5963 <p>Conformance to CSS Fonts Level 3 Module is defined for three conformance
jdaggett@7242 5964 classes:
jdaggett@7242 5965
jdaggett@7242 5966 <dl>
jdaggett@7243 5967 <dt><dfn id=style-sheet title="style sheet!!as conformance class">style
jdaggett@7242 5968 sheet</dfn>
jdaggett@7242 5969
jdaggett@7242 5970 <dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#style-sheet">CSS
jdaggett@7242 5971 style sheet</a>.
jdaggett@7242 5972
jdaggett@7243 5973 <dt><dfn id=renderer>renderer</dfn>
jdaggett@7242 5974
jdaggett@7242 5975 <dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#user-agent">UA</a>
jdaggett@7242 5976 that interprets the semantics of a style sheet and renders documents that
jdaggett@7242 5977 use them.
jdaggett@7242 5978
jdaggett@7242 5979 <dt><dfn id=authoring-tool>authoring tool</dfn>
jdaggett@7242 5980
jdaggett@7242 5981 <dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#user-agent">UA</a>
jdaggett@7242 5982 that writes a style sheet.
jdaggett@7242 5983 </dl>
jdaggett@7242 5984
jdaggett@7242 5985 <p>A style sheet is conformant to CSS Fonts Level 3 Module if all of its
jdaggett@7242 5986 declarations that use properties defined in this module have values that
jdaggett@7242 5987 are valid according to the generic CSS grammar and the individual grammars
jdaggett@7242 5988 of each property as given in this module.
jdaggett@7242 5989
jdaggett@7242 5990 <p>A renderer is conformant to CSS Fonts Level 3 Module if, in addition to
jdaggett@7242 5991 interpreting the style sheet as defined by the appropriate specifications,
jdaggett@7242 5992 it supports all the features defined by CSS Fonts Level 3 Module by
jdaggett@7242 5993 parsing them correctly and rendering the document accordingly. However,
jdaggett@7242 5994 the inability of a UA to correctly render a document due to limitations of
jdaggett@7242 5995 the device does not make the UA non-conformant. (For example, a UA is not
jdaggett@7242 5996 required to render color on a monochrome monitor.)
jdaggett@7242 5997
jdaggett@7242 5998 <p>An authoring tool is conformant to CSS Fonts Level 3 Module if it writes
jdaggett@7242 5999 style sheets that are syntactically correct according to the generic CSS
jdaggett@7242 6000 grammar and the individual grammars of each feature in this module, and
jdaggett@7242 6001 meet all other conformance requirements of style sheets as described in
jdaggett@7242 6002 this module.
jdaggett@7242 6003
jdaggett@7242 6004 <h3 class=no-num id=partial> Partial Implementations</h3>
jdaggett@7242 6005
jdaggett@7242 6006 <p>So that authors can exploit the forward-compatible parsing rules to
jdaggett@7242 6007 assign fallback values, CSS renderers <strong>must</strong> treat as
jdaggett@7242 6008 invalid (and <a
jdaggett@7242 6009 href="http://www.w3.org/TR/CSS21/conform.html#ignore">ignore as
jdaggett@7242 6010 appropriate</a>) any at-rules, properties, property values, keywords, and
jdaggett@7242 6011 other syntactic constructs for which they have no usable level of support.
jdaggett@7242 6012 In particular, user agents <strong>must not</strong> selectively ignore
jdaggett@7242 6013 unsupported component values and honor supported values in a single
jdaggett@7242 6014 multi-value property declaration: if any value is considered invalid (as
jdaggett@7242 6015 unsupported values must be), CSS requires that the entire declaration be
jdaggett@7242 6016 ignored.
jdaggett@7242 6017
jdaggett@7242 6018 <h3 class=no-num id=experimental> Experimental Implementations</h3>
jdaggett@7242 6019
jdaggett@7242 6020 <p>To avoid clashes with future CSS features, the CSS2.1 specification
jdaggett@7242 6021 reserves a <a
jdaggett@7242 6022 href="http://www.w3.org/TR/CSS21/syndata.html#vendor-keywords">prefixed
jdaggett@7242 6023 syntax</a> for proprietary and experimental extensions to CSS.
jdaggett@7242 6024
jdaggett@7242 6025 <p>Prior to a specification reaching the Candidate Recommendation stage in
jdaggett@7242 6026 the W3C process, all implementations of a CSS feature are considered
jdaggett@7242 6027 experimental. The CSS Working Group recommends that implementations use a
jdaggett@7242 6028 vendor-prefixed syntax for such features, including those in W3C Working
jdaggett@7242 6029 Drafts. This avoids incompatibilities with future changes in the draft.
jdaggett@7242 6030
jdaggett@7242 6031 <h3 class=no-num id=testing> Non-Experimental Implementations</h3>
jdaggett@7242 6032
jdaggett@7242 6033 <p>Once a specification reaches the Candidate Recommendation stage,
jdaggett@7242 6034 non-experimental implementations are possible, and implementors should
jdaggett@7242 6035 release an unprefixed implementation of any CR-level feature they can
jdaggett@7242 6036 demonstrate to be correctly implemented according to spec.
jdaggett@7242 6037
jdaggett@7242 6038 <p>To establish and maintain the interoperability of CSS across
jdaggett@7242 6039 implementations, the CSS Working Group requests that non-experimental CSS
jdaggett@7242 6040 renderers submit an implementation report (and, if necessary, the
jdaggett@7242 6041 testcases used for that implementation report) to the W3C before releasing
jdaggett@7242 6042 an unprefixed implementation of any CSS features. Testcases submitted to
jdaggett@7242 6043 W3C are subject to review and correction by the CSS Working Group.
jdaggett@7242 6044
jdaggett@7242 6045 <p>Further information on submitting testcases and implementation reports
jdaggett@7242 6046 can be found from on the CSS Working Group's website at <a
jdaggett@7242 6047 href="http://www.w3.org/Style/CSS/Test/">http://www.w3.org/Style/CSS/Test/</a>.
jdaggett@7242 6048 Questions should be directed to the <a
jdaggett@7242 6049 href="http://lists.w3.org/Archives/Public/public-css-testsuite">public-css-testsuite@w3.org</a>
jdaggett@7242 6050 mailing list.
jdaggett@7242 6051
jdaggett@484 6052 <h2 class=no-num id=references>References</h2>
jdaggett@484 6053
jdaggett@1662 6054 <h3 class=no-num id=normative-references>Normative References</h3>
jdaggett@484 6055 <!--begin-normative-->
jdaggett@484 6056 <!-- Sorted by label -->
jdaggett@484 6057
jdaggett@484 6058 <dl class=bibliography>
jdaggett@8031 6059 <dd style="display: none"><!-- keeps the doc valid if the DL is empty -->
jdaggett@484 6060 <!---->
jdaggett@531 6061
jdaggett@2461 6062 <dt id=CHARMOD>[CHARMOD]
jdaggett@2461 6063
jdaggett@2461 6064 <dd>Martin J. Dürst; et al. <a
jdaggett@2737 6065 href="http://www.w3.org/TR/2005/REC-charmod-20050215/"><cite>Character
jdaggett@2461 6066 Model for the World Wide Web 1.0: Fundamentals.</cite></a> 15 February
jdaggett@2461 6067 2005. W3C Recommendation. URL: <a
jdaggett@2737 6068 href="http://www.w3.org/TR/2005/REC-charmod-20050215/">http://www.w3.org/TR/2005/REC-charmod-20050215/</a>
jdaggett@2461 6069 </dd>
jdaggett@2461 6070 <!---->
jdaggett@2461 6071
jdaggett@2457 6072 <dt id=CORS>[CORS]
jdaggett@1662 6073
jdaggett@1662 6074 <dd>Anne van Kesteren. <a
jdaggett@7242 6075 href="http://www.w3.org/TR/2013/CR-cors-20130129/"><cite>Cross-Origin
jdaggett@7242 6076 Resource Sharing.</cite></a> 29 January 2013. W3C Candidate
jdaggett@7242 6077 Recommendation. (Work in progress.) URL: <a
jdaggett@7242 6078 href="http://www.w3.org/TR/2013/CR-cors-20130129/">http://www.w3.org/TR/2013/CR-cors-20130129/</a>
jdaggett@1662 6079 </dd>
jdaggett@1662 6080 <!---->
jdaggett@1662 6081
jdaggett@3041 6082 <dt id=CSS21>[CSS21]
jdaggett@3041 6083
jdaggett@3041 6084 <dd>Bert Bos; et al. <a
jdaggett@8031 6085 href="http://www.w3.org/TR/2011/REC-CSS2-20110607"><cite>Cascading Style
jdaggett@3041 6086 Sheets Level 2 Revision 1 (CSS 2.1) Specification.</cite></a> 7 June
jdaggett@3041 6087 2011. W3C Recommendation. URL: <a
jdaggett@8031 6088 href="http://www.w3.org/TR/2011/REC-CSS2-20110607">http://www.w3.org/TR/2011/REC-CSS2-20110607</a>
jdaggett@3041 6089 </dd>
jdaggett@3041 6090 <!---->
jdaggett@3041 6091
jdaggett@5833 6092 <dt id=CSS3VAL>[CSS3VAL]
jdaggett@5833 6093
jdaggett@5833 6094 <dd>Håkon Wium Lie; Tab Atkins; Elika J. Etemad. <a
jdaggett@8386 6095 href="http://www.w3.org/TR/2013/CR-css3-values-20130404/"><cite>CSS
jdaggett@8386 6096 Values and Units Module Level 3.</cite></a> 4 April 2013. W3C Candidate
jdaggett@6701 6097 Recommendation. (Work in progress.) URL: <a
jdaggett@8386 6098 href="http://www.w3.org/TR/2013/CR-css3-values-20130404/">http://www.w3.org/TR/2013/CR-css3-values-20130404/</a>
jdaggett@5833 6099 </dd>
jdaggett@5833 6100 <!---->
jdaggett@5833 6101
jdaggett@1662 6102 <dt id=HTML5>[HTML5]
jdaggett@1662 6103
jdaggett@1856 6104 <dd>Ian Hickson. <a
jdaggett@7242 6105 href="http://www.w3.org/TR/2012/CR-html5-20121217/"><cite>HTML5.</cite></a>
jdaggett@7242 6106 17 December 2012. W3C Candidate Recommendation. (Work in progress.) URL:
jdaggett@7242 6107 <a
jdaggett@7242 6108 href="http://www.w3.org/TR/2012/CR-html5-20121217/">http://www.w3.org/TR/2012/CR-html5-20121217/</a>
jdaggett@1662 6109 </dd>
jdaggett@1662 6110 <!---->
jdaggett@1662 6111
jdaggett@1662 6112 <dt id=OPEN-FONT-FORMAT>[OPEN-FONT-FORMAT]
jdaggett@1662 6113
jdaggett@1662 6114 <dd><a
bert@8683 6115 href="http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=52136"><cite>Information
jdaggett@1662 6116 technology — Coding of audio-visual objects — Part 22: Open Font
jdaggett@1662 6117 Format.</cite></a> International Organization for Standardization.
jdaggett@1662 6118 ISO/IEC 14496-22:2009. URL: <a
bert@8683 6119 href="http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=52136">http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=52136</a>
jdaggett@1662 6120 </dd>
jdaggett@1662 6121 <!---->
jdaggett@1662 6122
jdaggett@1662 6123 <dt id=OPENTYPE>[OPENTYPE]
jdaggett@1662 6124
jdaggett@1662 6125 <dd><a
jdaggett@1662 6126 href="http://www.microsoft.com/typography/otspec/default.htm"><cite>OpenType
jdaggett@1662 6127 specification.</cite></a> Microsoft. URL: <a
jdaggett@1662 6128 href="http://www.microsoft.com/typography/otspec/default.htm">http://www.microsoft.com/typography/otspec/default.htm</a>
jdaggett@1662 6129 </dd>
jdaggett@1662 6130 <!---->
jdaggett@1662 6131
jdaggett@1662 6132 <dt id=OPENTYPE-FEATURES>[OPENTYPE-FEATURES]
jdaggett@1662 6133
jdaggett@1662 6134 <dd><a
jdaggett@1662 6135 href="http://www.microsoft.com/typography/otspec/featurelist.htm"><cite>OpenType
jdaggett@1662 6136 feature registry.</cite></a> Microsoft. URL: <a
jdaggett@1662 6137 href="http://www.microsoft.com/typography/otspec/featurelist.htm">http://www.microsoft.com/typography/otspec/featurelist.htm</a>
jdaggett@1662 6138 </dd>
jdaggett@1662 6139 <!---->
jdaggett@1662 6140
jdaggett@7103 6141 <dt id=RFC2119>[RFC2119]
jdaggett@7103 6142
jdaggett@7103 6143 <dd>S. Bradner. <a href="http://www.ietf.org/rfc/rfc2119.txt"><cite>Key
jdaggett@7103 6144 words for use in RFCs to Indicate Requirement Levels.</cite></a> Internet
jdaggett@7103 6145 RFC 2119. URL: <a
jdaggett@7103 6146 href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a>
jdaggett@7103 6147 </dd>
jdaggett@7103 6148 <!---->
jdaggett@7103 6149
jdaggett@2457 6150 <dt id=UAX15>[UAX15]
jdaggett@2457 6151
jdaggett@7242 6152 <dd>Mark Davis; Ken Whistler. <a
jdaggett@7242 6153 href="http://www.unicode.org/reports/tr15/"><cite>Unicode Normalization
jdaggett@7242 6154 Forms.</cite></a> 31 August 2012. Unicode Standard Annex #15. URL: <a
jdaggett@7242 6155 href="http://www.unicode.org/reports/tr15/">http://www.unicode.org/reports/tr15/</a>
jdaggett@2457 6156 </dd>
jdaggett@2457 6157 <!---->
jdaggett@2457 6158
jdaggett@1856 6159 <dt id=UAX29>[UAX29]
jdaggett@1856 6160
jdaggett@1856 6161 <dd>Mark Davis. <a
jdaggett@5809 6162 href="http://www.unicode.org/reports/tr29/"><cite>Unicode Text
jdaggett@7242 6163 Segmentation.</cite></a> 12 September 2012. Unicode Standard Annex #29.
jdaggett@2461 6164 URL: <a
jdaggett@5809 6165 href="http://www.unicode.org/reports/tr29/">http://www.unicode.org/reports/tr29/</a>
jdaggett@1856 6166 </dd>
jdaggett@1856 6167 <!---->
jdaggett@1856 6168
jdaggett@3041 6169 <dt id=UNICODE6>[UNICODE6]
jdaggett@531 6170
jdaggett@531 6171 <dd>The Unicode Consortium. <a
jdaggett@7242 6172 href="http://www.unicode.org/versions/Unicode6.2.0/"><cite>The Unicode
jdaggett@7242 6173 Standard, Version 6.2.0.</cite></a> Defined by: The Unicode Standard,
jdaggett@7242 6174 Version 6.2.0 URL: <a
jdaggett@7242 6175 href="http://www.unicode.org/versions/Unicode6.2.0/">http://www.unicode.org/versions/Unicode6.2.0/</a>
jdaggett@531 6176 </dd>
jdaggett@531 6177 <!---->
jdaggett@484 6178 </dl>
jdaggett@484 6179 <!--end-normative-->
jdaggett@3041 6180 <!--{{!CSS21}}-->
jdaggett@5833 6181 <!--{{!CSS3VAL}}-->
jdaggett@1662 6182 <!--{{!OPENTYPE}}-->
jdaggett@1662 6183 <!--{{!OPENTYPE-FEATURES}}-->
jdaggett@1662 6184 <!--{{!OPEN-FONT-FORMAT}}-->
jdaggett@3041 6185 <!--{{!UNICODE6}}-->
jdaggett@2457 6186 <!--{{!UAX15}}-->
jdaggett@1856 6187 <!--{{!UAX29}}-->
jdaggett@2457 6188 <!--{{!CORS}}-->
jdaggett@1662 6189 <!--{{!HTML5}}-->
jdaggett@2461 6190 <!--{{!CHARMOD}}-->
jdaggett@1662 6191
jdaggett@1662 6192 <h3 class=no-num id=other-references>Other References</h3>
jdaggett@484 6193 <!--begin-informative-->
jdaggett@484 6194 <!-- Sorted by label -->
jdaggett@484 6195
jdaggett@484 6196 <dl class=bibliography>
jdaggett@8031 6197 <dd style="display: none"><!-- keeps the doc valid if the DL is empty -->
jdaggett@484 6198 <!---->
jdaggett@484 6199
jdaggett@3042 6200 <dt id=AAT-FEATURES>[AAT-FEATURES]
jdaggett@3042 6201
jdaggett@3042 6202 <dd><a href="http://developer.apple.com/fonts/registry/"><cite>Apple
jdaggett@3042 6203 Advanced Typography font feature registry.</cite></a> Apple. URL: <a
jdaggett@3042 6204 href="http://developer.apple.com/fonts/registry/">http://developer.apple.com/fonts/registry/</a>
jdaggett@3042 6205 </dd>
jdaggett@3042 6206 <!---->
jdaggett@3042 6207
jdaggett@512 6208 <dt id=ARABIC-TYPO>[ARABIC-TYPO]
jdaggett@512 6209
jdaggett@513 6210 <dd>Huda Smitshuijzen AbiFares. <cite>Arabic Typography: A Comprehensive
jdaggett@1148 6211 Sourcebook.</cite> Saqi Books. 2001. ISBN 0-86356-347-3.</dd>
jdaggett@512 6212 <!---->
jdaggett@512 6213
jdaggett@3042 6214 <dt id=CHARMOD-NORM>[CHARMOD-NORM]
jdaggett@3042 6215
jdaggett@3042 6216 <dd>François Yergeau; et al. <a
jdaggett@5809 6217 href="http://www.w3.org/TR/2012/WD-charmod-norm-20120501/"><cite>Character
jdaggett@5809 6218 Model for the World Wide Web 1.0: Normalization.</cite></a> 1 May 2012.
jdaggett@5809 6219 W3C Working Draft. (Work in progress.) URL: <a
jdaggett@5809 6220 href="http://www.w3.org/TR/2012/WD-charmod-norm-20120501/">http://www.w3.org/TR/2012/WD-charmod-norm-20120501/</a>
jdaggett@3042 6221 </dd>
jdaggett@3042 6222 <!---->
jdaggett@3042 6223
jdaggett@1732 6224 <dt id=CJKV-INFO-PROCESSING>[CJKV-INFO-PROCESSING]
jdaggett@1732 6225
jdaggett@1732 6226 <dd>Ken Lunde. <cite>CJKV Information Processing, Second Edition.</cite>
jdaggett@1732 6227 O'Reilly Media, Inc. 2009. ISBN 0-596-51447-1.</dd>
jdaggett@1732 6228 <!---->
jdaggett@1732 6229
jdaggett@3460 6230 <dt id=CSS3-CONDITIONAL>[CSS3-CONDITIONAL]
jdaggett@3460 6231
jdaggett@3460 6232 <dd>L. David Baron. <a
jdaggett@8386 6233 href="http://www.w3.org/TR/2013/CR-css3-conditional-20130404/"><cite>CSS
jdaggett@8386 6234 Conditional Rules Module Level 3.</cite></a> 4 April 2013. W3C Candidate
jdaggett@8386 6235 Recommendation. (Work in progress.) URL: <a
jdaggett@8386 6236 href="http://www.w3.org/TR/2013/CR-css3-conditional-20130404/">http://www.w3.org/TR/2013/CR-css3-conditional-20130404/</a>
jdaggett@3460 6237 </dd>
jdaggett@3460 6238 <!---->
jdaggett@3460 6239
jdaggett@6701 6240 <dt id=CSS3TEXT>[CSS3TEXT]
jdaggett@6701 6241
jdaggett@6701 6242 <dd>Elika J. Etemad; Koji Ishii. <a
jdaggett@7041 6243 href="http://www.w3.org/TR/2012/WD-css3-text-20121113/"><cite>CSS Text
jdaggett@7041 6244 Module Level 3.</cite></a> 13 November 2012. W3C Working Draft. (Work in
jdaggett@6701 6245 progress.) URL: <a
jdaggett@7041 6246 href="http://www.w3.org/TR/2012/WD-css3-text-20121113/">http://www.w3.org/TR/2012/WD-css3-text-20121113/</a>
jdaggett@6701 6247 </dd>
jdaggett@6701 6248 <!---->
jdaggett@6701 6249
jdaggett@1856 6250 <dt id=DIGITAL-TYPOGRAPHY>[DIGITAL-TYPOGRAPHY]
jdaggett@1856 6251
jdaggett@1856 6252 <dd>Richard Rubinstein. <cite>Digital Typography, An Introduction to Type
jdaggett@1856 6253 and Composition for Computer System Design.</cite> Addison-Wesley. 1988.
jdaggett@1856 6254 ISBN 0-201-17633-5.</dd>
jdaggett@1856 6255 <!---->
jdaggett@1856 6256
jdaggett@7022 6257 <dt id=DOM-LEVEL-2-STYLE>[DOM-LEVEL-2-STYLE]
jdaggett@7022 6258
jdaggett@7022 6259 <dd>Chris Wilson; Philippe Le Hégaret; Vidur Apparao. <a
jdaggett@7179 6260 href="http://www.w3.org/TR/2000/REC-DOM-Level-2-Style-20001113/"><cite>Document
jdaggett@7022 6261 Object Model (DOM) Level 2 Style Specification.</cite></a> 13 November
jdaggett@7022 6262 2000. W3C Recommendation. URL: <a
jdaggett@7179 6263 href="http://www.w3.org/TR/2000/REC-DOM-Level-2-Style-20001113/">http://www.w3.org/TR/2000/REC-DOM-Level-2-Style-20001113/</a>
jdaggett@7022 6264 </dd>
jdaggett@7022 6265 <!---->
jdaggett@7022 6266
jdaggett@498 6267 <dt id=ELEMTYPO>[ELEMTYPO]
jdaggett@498 6268
jdaggett@498 6269 <dd>Robert Bringhurst. <cite>The Elements of Typographic Style, Version
jdaggett@7488 6270 4.</cite> Hartley &amp; Marks. 2013. ISBN 0-88179-212-8.</dd>
jdaggett@498 6271 <!---->
jdaggett@498 6272
jdaggett@513 6273 <dt id=LANGCULTTYPE>[LANGCULTTYPE]
jdaggett@513 6274
jdaggett@1148 6275 <dd>John D. Berry, Ed. <cite>Language Culture Type.</cite> Graphis. 2001.
jdaggett@1148 6276 ISBN 1-932026-01-0.</dd>
jdaggett@512 6277 <!---->
jdaggett@1662 6278
jdaggett@1662 6279 <dt id=OPENTYPE-FONT-GUIDE>[OPENTYPE-FONT-GUIDE]
jdaggett@1662 6280
jdaggett@1662 6281 <dd><a
jdaggett@3538 6282 href="https://www.fontfont.com/staticcontent/downloads/FF_OT_User_Guide.pdf"><cite>OpenType
jdaggett@1662 6283 User Guide.</cite></a> FontShop International. URL: <a
jdaggett@3538 6284 href="https://www.fontfont.com/staticcontent/downloads/FF_OT_User_Guide.pdf">https://www.fontfont.com/staticcontent/downloads/FF_OT_User_Guide.pdf</a>
jdaggett@1662 6285 </dd>
jdaggett@1662 6286 <!---->
jdaggett@1856 6287
jdaggett@2527 6288 <dt id=RASTER-TRAGEDY>[RASTER-TRAGEDY]
jdaggett@2527 6289
jdaggett@2527 6290 <dd>Beat Stamm. <a href="http://www.rastertragedy.com/"><cite>The Raster
jdaggett@6659 6291 Tragedy at Low-Resolution Revisited.</cite></a> 7 December 2011. URL: <a
jdaggett@2527 6292 href="http://www.rastertragedy.com/">http://www.rastertragedy.com/</a></dd>
jdaggett@2527 6293 <!---->
jdaggett@2527 6294
jdaggett@1856 6295 <dt id=WINDOWS-GLYPH-PROC>[WINDOWS-GLYPH-PROC]
jdaggett@1856 6296
jdaggett@1856 6297 <dd>John Hudson. <a
jdaggett@1856 6298 href="http://www.microsoft.com/typography/developers/opentype/default.htm"><cite>Windows
jdaggett@1856 6299 Glyph Processing.</cite></a> Microsoft Typogrraphy. URL: <a
jdaggett@1856 6300 href="http://www.microsoft.com/typography/developers/opentype/default.htm">http://www.microsoft.com/typography/developers/opentype/default.htm</a>
jdaggett@1856 6301 </dd>
jdaggett@1856 6302 <!---->
jdaggett@484 6303 </dl>
jdaggett@484 6304 <!--end-informative-->
jdaggett@518 6305 <!--{{ARABIC-TYPO}}-->
jdaggett@1732 6306 <!--{{CJKV-INFO-PROCESSING}}-->
jdaggett@1856 6307 <!--{{DIGITAL-TYPOGRAPHY}}-->
jdaggett@7022 6308 <!--{{DOM-LEVEL-2-STYLE}}-->
jdaggett@518 6309 <!--{{ELEMTYPO}}-->
jdaggett@1856 6310 <!--{{LANGCULTTYPE}}-->
jdaggett@1662 6311 <!--{{OPENTYPE-FONT-GUIDE}}-->
jdaggett@2527 6312 <!--{{RASTER-TRAGEDY}}-->
jdaggett@1856 6313 <!--{{WINDOWS-GLYPH-PROC}}-->
jdaggett@3042 6314 <!--{{CHARMOD-NORM}}-->
jdaggett@3042 6315 <!--{{AAT-FEATURES}}-->
jdaggett@3460 6316 <!--{{CSS3-CONDITIONAL}}-->
jdaggett@6701 6317 <!--{{CSS3TEXT}}-->
jdaggett@484 6318
jdaggett@484 6319 <h2 class=no-num id=index>Index</h2>
jdaggett@484 6320 <!--begin-index-->
jdaggett@484 6321
jdaggett@484 6322 <ul class=indexlist>
jdaggett@8278 6323 <li>100...900 weight values, <a href="#font-weight-numeric-values"
jdaggett@8278 6324 title="100...900 weight values"><strong>3.2</strong></a>
jdaggett@8278 6325
jdaggett@8225 6326 <li><var>&lt;absolute-size&gt;</var>, <a href="#absolute-size-value"
jdaggett@7060 6327 title="&lt;absolute-size&gt;"><strong>3.5</strong></a>
jdaggett@890 6328
jdaggett@8225 6329 <li><var>&lt;common-lig-values&gt;</var>, <a href="#common-lig-values"
jdaggett@8225 6330 title="&lt;common-lig-values&gt;"><strong>6.4</strong></a>
jdaggett@2479 6331
jdaggett@2479 6332 <li><var>&lt;contextual-alt-values&gt;</var>, <a
jdaggett@8225 6333 href="#contextual-alt-values"
jdaggett@6176 6334 title="&lt;contextual-alt-values&gt;"><strong>6.4</strong></a>
jdaggett@2479 6335
jdaggett@8225 6336 <li><var>&lt;discretionary-lig-values&gt;</var>, <a
jdaggett@8225 6337 href="#discretionary-lig-values"
jdaggett@8225 6338 title="&lt;discretionary-lig-values&gt;"><strong>6.4</strong></a>
jdaggett@3460 6339
jdaggett@2479 6340 <li><var>&lt;east-asian-variant-values&gt;</var>, <a
jdaggett@8225 6341 href="#east-asian-variant-values"
jdaggett@2479 6342 title="&lt;east-asian-variant-values&gt;"><strong>6.10</strong></a>
jdaggett@2479 6343
jdaggett@2479 6344 <li><var>&lt;east-asian-width-values&gt;</var>, <a
jdaggett@8225 6345 href="#east-asian-width-values"
jdaggett@2479 6346 title="&lt;east-asian-width-values&gt;"><strong>6.10</strong></a>
jdaggett@2479 6347
jdaggett@8225 6348 <li><var>&lt;family-name&gt;</var>, <a href="#family-name-value"
jdaggett@8225 6349 title="&lt;family-name&gt;"><strong>3.1</strong></a>
jdaggett@8225 6350
jdaggett@8225 6351 <li><var>&lt;feature-tag-value&gt;</var>, <a href="#feature-tag-value"
jdaggett@2515 6352 title="&lt;feature-tag-value&gt;"><strong>6.12</strong></a>
jdaggett@2515 6353
jdaggett@8225 6354 <li><var>&lt;font-face-name&gt;</var>, <a href="#font-face-name-value"
jdaggett@7060 6355 title="&lt;font-face-name&gt;"><strong>4.3</strong></a>
jdaggett@4624 6356
jdaggett@4624 6357 <li><var>&lt;font-variant-css21&gt;</var>, <a
jdaggett@8225 6358 href="#font-variant-css21-values"
jdaggett@4624 6359 title="&lt;font-variant-css21&gt;"><strong>3.7</strong></a>
jdaggett@4624 6360
jdaggett@8225 6361 <li><var>&lt;generic-family&gt;</var>, <a href="#generic-family-value"
jdaggett@8225 6362 title="&lt;generic-family&gt;"><strong>3.1</strong></a>
jdaggett@8225 6363
jdaggett@8225 6364 <li><var>&lt;historical-lig-values&gt;</var>, <a
jdaggett@8225 6365 href="#historical-lig-values"
jdaggett@8225 6366 title="&lt;historical-lig-values&gt;"><strong>6.4</strong></a>
jdaggett@8225 6367
jdaggett@8225 6368 <li><var>&lt;length&gt;</var>, <a href="#length-size-value"
jdaggett@8225 6369 title="&lt;length&gt;"><strong>3.5</strong></a>
jdaggett@8225 6370
jdaggett@8225 6371 <li><var>&lt;number&gt;</var>, <a href="#aspect-ratio-value"
jdaggett@8225 6372 title="&lt;number&gt;"><strong>3.6</strong></a>
jdaggett@4624 6373
jdaggett@4624 6374 <li><var>&lt;numeric-figure-values&gt;</var>, <a
jdaggett@8225 6375 href="#numeric-figure-values"
jdaggett@4624 6376 title="&lt;numeric-figure-values&gt;"><strong>6.7</strong></a>
jdaggett@4624 6377
jdaggett@4624 6378 <li><var>&lt;numeric-fraction-values&gt;</var>, <a
jdaggett@8225 6379 href="#numeric-fraction-values"
jdaggett@4624 6380 title="&lt;numeric-fraction-values&gt;"><strong>6.7</strong></a>
jdaggett@4624 6381
jdaggett@4624 6382 <li><var>&lt;numeric-spacing-values&gt;</var>, <a
jdaggett@8225 6383 href="#numeric-spacing-values"
jdaggett@4624 6384 title="&lt;numeric-spacing-values&gt;"><strong>6.7</strong></a>
jdaggett@4624 6385
jdaggett@8225 6386 <li><var>&lt;percentage&gt;</var>, <a href="#percentage-size-value"
jdaggett@8225 6387 title="&lt;percentage&gt;"><strong>3.5</strong></a>
jdaggett@8225 6388
jdaggett@8225 6389 <li><var>&lt;relative-size&gt;</var>, <a href="#relative-size-value"
jdaggett@7060 6390 title="&lt;relative-size&gt;"><strong>3.5</strong></a>
jdaggett@7060 6391
jdaggett@8278 6392 <li><var>&lt;string&gt;</var>, <a
jdaggett@8278 6393 href="#font-language-override-string-value"
jdaggett@8278 6394 title="&lt;string&gt;"><strong>6.13</strong></a>
jdaggett@8278 6395
jdaggett@8225 6396 <li><var>&lt;urange&gt;</var>, <a href="#urange-value"
jdaggett@8225 6397 title="&lt;urange&gt;"><strong>4.5</strong></a>
jdaggett@2479 6398
jdaggett@8311 6399 <li><code>@font-face</code>, <a href="#at-font-face-rule"
jdaggett@8311 6400 title="@font-face"><strong>4.1</strong></a>
jdaggett@8311 6401
jdaggett@8311 6402 <li><code>@font-feature-values</code>, <a
jdaggett@8311 6403 href="#at-font-feature-values-rule"
jdaggett@8311 6404 title="@font-feature-values"><strong>6.9</strong></a>
jdaggett@2479 6405
jdaggett@4624 6406 <li>all-petite-caps, <a href="#all-petite-caps"
jdaggett@4624 6407 title=all-petite-caps><strong>6.6</strong></a>
jdaggett@4624 6408
jdaggett@4624 6409 <li>all-small-caps, <a href="#all-small-caps"
jdaggett@4624 6410 title=all-small-caps><strong>6.6</strong></a>
jdaggett@4624 6411
jdaggett@8225 6412 <li>annotation, <a href="#annotation"
jdaggett@7060 6413 title=annotation><strong>6.8</strong></a>
jdaggett@4624 6414
jdaggett@4624 6415 <li>aspect value, <a href="#aspect-value0" title="aspect
jdaggett@4624 6416 value"><strong>3.6</strong></a>
jdaggett@4624 6417
jdaggett@7103 6418 <li>authoring tool, <a href="#authoring-tool" title="authoring
jdaggett@7243 6419 tool"><strong>#</strong></a>
jdaggett@7103 6420
jdaggett@8278 6421 <li>auto
jdaggett@8278 6422 <ul>
jdaggett@8278 6423 <li>font-kerning, <a href="#font-kerning-auto-value" title="auto,
jdaggett@8278 6424 font-kerning"><strong>6.3</strong></a>
jdaggett@8278 6425
jdaggett@8278 6426 <li>font-size-adjust, <a href="#font-size-adjust-auto-value"
jdaggett@8278 6427 title="auto, font-size-adjust"><strong>3.6</strong></a>
jdaggett@8278 6428 </ul>
jdaggett@8278 6429
jdaggett@8278 6430 <li>bold, <a href="#bold" title=bold><strong>3.2</strong></a>
jdaggett@8278 6431
jdaggett@8278 6432 <li>bolder, <a href="#bolder" title=bolder><strong>3.2</strong></a>
jdaggett@8278 6433
jdaggett@7311 6434 <li>character map, <a href="#character-map" title="character
jdaggett@7311 6435 map"><strong>5.2</strong></a>
jdaggett@7311 6436
jdaggett@8225 6437 <li>character-variant, <a href="#character-variant"
jdaggett@7060 6438 title=character-variant><strong>6.8</strong></a>
jdaggett@4624 6439
jdaggett@4624 6440 <li>common-ligatures, <a href="#common-ligatures"
jdaggett@6176 6441 title=common-ligatures><strong>6.4</strong></a>
jdaggett@4624 6442
jdaggett@8391 6443 <li>composite face, <a href="#composite-face" title="composite
jdaggett@8391 6444 face"><strong>5.2</strong></a>
jdaggett@8391 6445
jdaggett@8278 6446 <li>condensed, <a href="#condensed"
jdaggett@8278 6447 title=condensed><strong>3.3</strong></a>
jdaggett@8278 6448
jdaggett@4624 6449 <li>contextual, <a href="#contextual"
jdaggett@6176 6450 title=contextual><strong>6.4</strong></a>
jdaggett@4624 6451
jdaggett@7021 6452 <li>CSSFontFaceRule, <a href="#cssfontfacerule"
jdaggett@7021 6453 title=CSSFontFaceRule><strong>8.1</strong></a>
jdaggett@7021 6454
jdaggett@7021 6455 <li>CSSFontFeatureValuesRule, <a href="#cssfontfeaturevaluesrule"
jdaggett@7021 6456 title=CSSFontFeatureValuesRule><strong>8.2</strong></a>
jdaggett@7021 6457
jdaggett@4624 6458 <li>cursive, definition of, <a href="#cursive0" title="cursive, definition
jdaggett@4624 6459 of"><strong>#</strong></a>
jdaggett@4624 6460
jdaggett@7232 6461 <li>default face, <a href="#default-face" title="default
jdaggett@7309 6462 face"><strong>5.2</strong></a>
jdaggett@7232 6463
jdaggett@8031 6464 <li>descriptor_declaration, <a href="#descriptordeclaration"
jdaggett@8031 6465 title="descriptor_declaration"><strong>4.1</strong></a>
jdaggett@8031 6466
jdaggett@4624 6467 <li>diagonal-fractions, <a href="#diagonal-fractions"
jdaggett@4624 6468 title=diagonal-fractions><strong>6.7</strong></a>
jdaggett@4624 6469
jdaggett@4624 6470 <li>discretionary-ligatures, <a href="#discretionary-ligatures"
jdaggett@6176 6471 title=discretionary-ligatures><strong>6.4</strong></a>
jdaggett@4624 6472
jdaggett@8391 6473 <li>effective character map, <a href="#effective-character-map"
jdaggett@8391 6474 title="effective character map"><strong>4.5</strong></a>
jdaggett@8391 6475
jdaggett@8278 6476 <li>expanded, <a href="#expanded" title=expanded><strong>3.3</strong></a>
jdaggett@8278 6477
jdaggett@8278 6478 <li>extra-condensed, <a href="#extra-condensed"
jdaggett@8278 6479 title=extra-condensed><strong>3.3</strong></a>
jdaggett@8278 6480
jdaggett@8278 6481 <li>extra-expanded, <a href="#extra-expanded"
jdaggett@8278 6482 title=extra-expanded><strong>3.3</strong></a>
jdaggett@8278 6483
jdaggett@4624 6484 <li>fantasy, definition of, <a href="#fantasy0" title="fantasy, definition
jdaggett@4624 6485 of"><strong>#</strong></a>
jdaggett@4624 6486
jdaggett@8031 6487 <li>feature_type, <a href="#featuretype"
jdaggett@8356 6488 title="feature_type"><strong>6.9.1</strong></a>
jdaggett@8031 6489
jdaggett@8031 6490 <li>feature_value_block, <a href="#featurevalueblock"
jdaggett@8356 6491 title="feature_value_block"><strong>6.9.1</strong></a>
jdaggett@8031 6492
jdaggett@8031 6493 <li>feature_value_definition, <a href="#featurevaluedefinition"
jdaggett@8356 6494 title="feature_value_definition"><strong>6.9.1</strong></a>
jdaggett@7679 6495
jdaggett@8431 6496 <li>first available font, <a href="#first-available-font" title="first
jdaggett@8431 6497 available font"><strong>5.2</strong></a>
jdaggett@8431 6498
jdaggett@4624 6499 <li>font, <a href="#propdef-font" title=font><strong>3.7</strong></a>
jdaggett@2472 6500
jdaggett@8356 6501 <li>font specific, <a href="#font-specific" title="font
jdaggett@8356 6502 specific"><strong>6.8</strong></a>
jdaggett@8356 6503
jdaggett@8278 6504 <li>font-family
jdaggett@8278 6505 <ul>
jdaggett@8278 6506 <li>descriptor, <a href="#descdef-font-family" title="font-family,
jdaggett@8278 6507 descriptor"><strong>4.2</strong></a>
jdaggett@8278 6508
jdaggett@8278 6509 <li>property, <a href="#propdef-font-family" title="font-family,
jdaggett@8278 6510 property"><strong>3.1</strong></a>
jdaggett@8278 6511 </ul>
jdaggett@1662 6512
jdaggett@8279 6513 <li>font-feature-settings
jdaggett@8278 6514 <ul>
jdaggett@8278 6515 <li>descriptor, <a href="#descdef-font-feature-settings"
jdaggett@8278 6516 title="font-feature-settings, descriptor"><strong>4.7</strong></a>
jdaggett@8279 6517
jdaggett@8279 6518 <li>property, <a href="#propdef-font-feature-settings"
jdaggett@8279 6519 title="font-feature-settings, property"><strong>6.12</strong></a>
jdaggett@8278 6520 </ul>
jdaggett@7060 6521
jdaggett@1662 6522 <li>font-kerning, <a href="#propdef-font-kerning"
jdaggett@1856 6523 title=font-kerning><strong>6.3</strong></a>
jdaggett@1662 6524
jdaggett@1732 6525 <li>font-language-override, <a href="#propdef-font-language-override"
jdaggett@2118 6526 title=font-language-override><strong>6.13</strong></a>
jdaggett@1662 6527
jdaggett@1662 6528 <li>font-size, <a href="#propdef-font-size"
jdaggett@1662 6529 title=font-size><strong>3.5</strong></a>
jdaggett@1662 6530
jdaggett@1662 6531 <li>font-size-adjust, <a href="#propdef-font-size-adjust"
jdaggett@1662 6532 title=font-size-adjust><strong>3.6</strong></a>
jdaggett@1662 6533
jdaggett@8278 6534 <li>font-stretch
jdaggett@8278 6535 <ul>
jdaggett@8278 6536 <li>descriptor, <a href="#descdef-font-stretch" title="font-stretch,
jdaggett@8278 6537 descriptor"><strong>4.4</strong></a>
jdaggett@8278 6538
jdaggett@8278 6539 <li>property, <a href="#propdef-font-stretch" title="font-stretch,
jdaggett@8278 6540 property"><strong>3.3</strong></a>
jdaggett@8278 6541 </ul>
jdaggett@8278 6542
jdaggett@8278 6543 <li>font-style
jdaggett@8278 6544 <ul>
jdaggett@8278 6545 <li>descriptor, <a href="#descdef-font-style" title="font-style,
jdaggett@8278 6546 descriptor"><strong>4.4</strong></a>
jdaggett@8278 6547
jdaggett@8278 6548 <li>property, <a href="#propdef-font-style" title="font-style,
jdaggett@8278 6549 property"><strong>3.4</strong></a>
jdaggett@8278 6550 </ul>
jdaggett@7060 6551
jdaggett@2487 6552 <li>font-synthesis, <a href="#propdef-font-synthesis"
jdaggett@2487 6553 title=font-synthesis><strong>3.8</strong></a>
jdaggett@2457 6554
jdaggett@8278 6555 <li>font-variant
jdaggett@8278 6556 <ul>
jdaggett@8278 6557 <li>descriptor, <a href="#descdef-font-variant" title="font-variant,
jdaggett@8278 6558 descriptor"><strong>4.7</strong></a>
jdaggett@8278 6559
jdaggett@8278 6560 <li>property, <a href="#propdef-font-variant" title="font-variant,
jdaggett@8278 6561 property"><strong>6.11</strong></a>
jdaggett@8278 6562 </ul>
jdaggett@1662 6563
jdaggett@1662 6564 <li>font-variant-alternates, <a href="#propdef-font-variant-alternates"
jdaggett@2118 6565 title=font-variant-alternates><strong>6.8</strong></a>
jdaggett@1662 6566
jdaggett@1662 6567 <li>font-variant-caps, <a href="#propdef-font-variant-caps"
jdaggett@2118 6568 title=font-variant-caps><strong>6.6</strong></a>
jdaggett@1732 6569
jdaggett@1662 6570 <li>font-variant-east-asian, <a href="#propdef-font-variant-east-asian"
jdaggett@2118 6571 title=font-variant-east-asian><strong>6.10</strong></a>
jdaggett@1662 6572
jdaggett@1662 6573 <li>font-variant-ligatures, <a href="#propdef-font-variant-ligatures"
jdaggett@6176 6574 title=font-variant-ligatures><strong>6.4</strong></a>
jdaggett@1662 6575
jdaggett@1662 6576 <li>font-variant-numeric, <a href="#propdef-font-variant-numeric"
jdaggett@2118 6577 title=font-variant-numeric><strong>6.7</strong></a>
jdaggett@2118 6578
jdaggett@3460 6579 <li>font-variant-position, <a href="#propdef-font-variant-position"
jdaggett@6176 6580 title=font-variant-position><strong>6.5</strong></a>
jdaggett@3460 6581
jdaggett@8278 6582 <li>font-weight
jdaggett@8278 6583 <ul>
jdaggett@8278 6584 <li>descriptor, <a href="#descdef-font-weight" title="font-weight,
jdaggett@8278 6585 descriptor"><strong>4.4</strong></a>
jdaggett@8278 6586
jdaggett@8278 6587 <li>property, <a href="#propdef-font-weight" title="font-weight,
jdaggett@8278 6588 property"><strong>3.2</strong></a>
jdaggett@8278 6589 </ul>
jdaggett@1662 6590
jdaggett@8031 6591 <li>font_face_rule, <a href="#fontfacerule"
jdaggett@8031 6592 title="font_face_rule"><strong>4.1</strong></a>
jdaggett@8031 6593
jdaggett@8225 6594 <li>FONT_FACE_SYM, <a href="#fontfacesym"
jdaggett@8225 6595 title="FONT_FACE_SYM"><strong>4.1</strong></a>
jdaggett@8225 6596
jdaggett@8031 6597 <li>font_family_name, <a href="#fontfamilyname"
jdaggett@8356 6598 title="font_family_name"><strong>6.9.1</strong></a>
jdaggett@8031 6599
jdaggett@8031 6600 <li>font_family_name_list, <a href="#fontfamilynamelist"
jdaggett@8356 6601 title="font_family_name_list"><strong>6.9.1</strong></a>
jdaggett@8031 6602
jdaggett@8031 6603 <li>font_feature_values_rule, <a href="#fontfeaturevaluesrule"
jdaggett@8356 6604 title="font_feature_values_rule"><strong>6.9.1</strong></a>
jdaggett@8031 6605
jdaggett@8225 6606 <li>FONT_FEATURE_VALUES_SYM, <a href="#fontfeaturevaluessym"
jdaggett@8356 6607 title="FONT_FEATURE_VALUES_SYM"><strong>6.9.1</strong></a>
jdaggett@8225 6608
jdaggett@1662 6609 <li>full-width, <a href="#full-width"
jdaggett@2118 6610 title=full-width><strong>6.10</strong></a>
jdaggett@1662 6611
jdaggett@1662 6612 <li>historical-forms, <a href="#historical-forms"
jdaggett@2118 6613 title=historical-forms><strong>6.8</strong></a>
jdaggett@1662 6614
jdaggett@1662 6615 <li>historical-ligatures, <a href="#historical-ligatures"
jdaggett@6176 6616 title=historical-ligatures><strong>6.4</strong></a>
jdaggett@1732 6617
jdaggett@8278 6618 <li>italic, <a href="#italic" title=italic><strong>3.4</strong></a>
jdaggett@8278 6619
jdaggett@2118 6620 <li>jis04, <a href="#jis04" title=jis04><strong>6.10</strong></a>
jdaggett@2118 6621
jdaggett@2118 6622 <li>jis78, <a href="#jis78" title=jis78><strong>6.10</strong></a>
jdaggett@2118 6623
jdaggett@2118 6624 <li>jis83, <a href="#jis83" title=jis83><strong>6.10</strong></a>
jdaggett@2118 6625
jdaggett@2118 6626 <li>jis90, <a href="#jis90" title=jis90><strong>6.10</strong></a>
jdaggett@1662 6627
jdaggett@8278 6628 <li>lighter, <a href="#lighter" title=lighter><strong>3.2</strong></a>
jdaggett@8278 6629
jdaggett@1662 6630 <li>lining-nums, <a href="#lining-nums"
jdaggett@2118 6631 title=lining-nums><strong>6.7</strong></a>
jdaggett@890 6632
jdaggett@890 6633 <li>monospace, definition of, <a href="#monospace0" title="monospace,
jdaggett@890 6634 definition of"><strong>#</strong></a>
jdaggett@890 6635
jdaggett@1662 6636 <li>no-common-ligatures, <a href="#no-common-ligatures"
jdaggett@6176 6637 title=no-common-ligatures><strong>6.4</strong></a>
jdaggett@1662 6638
jdaggett@1662 6639 <li>no-contextual, <a href="#no-contextual"
jdaggett@6176 6640 title=no-contextual><strong>6.4</strong></a>
jdaggett@1662 6641
jdaggett@3460 6642 <li>no-discretionary-ligatures, <a href="#no-discretionary-ligatures"
jdaggett@6176 6643 title=no-discretionary-ligatures><strong>6.4</strong></a>
jdaggett@3460 6644
jdaggett@1662 6645 <li>no-historical-ligatures, <a href="#no-historical-ligatures"
jdaggett@6176 6646 title=no-historical-ligatures><strong>6.4</strong></a>
jdaggett@1662 6647
jdaggett@8278 6648 <li>none
jdaggett@8278 6649 <ul>
jdaggett@8278 6650 <li>font-kerning, <a href="#font-kerning-none-value" title="none,
jdaggett@8278 6651 font-kerning"><strong>6.3</strong></a>
jdaggett@8278 6652
jdaggett@8278 6653 <li>font-size-adjust, <a href="#font-size-adjust-none-value"
jdaggett@8278 6654 title="none, font-size-adjust"><strong>3.6</strong></a>
jdaggett@8278 6655
jdaggett@8278 6656 <li>font-variant, <a href="#font-variant-none-value" title="none,
jdaggett@8278 6657 font-variant"><strong>6.11</strong></a>
jdaggett@8278 6658
jdaggett@8278 6659 <li>font-variant-ligatures, <a href="#font-variant-ligatures-none-value"
jdaggett@8278 6660 title="none, font-variant-ligatures"><strong>6.4</strong></a>
jdaggett@8278 6661 </ul>
jdaggett@8278 6662
jdaggett@8368 6663 <li>normal
jdaggett@8278 6664 <ul>
jdaggett@8278 6665 <li>font-feature-settings, <a href="#font-feature-settings-normal-value"
jdaggett@8278 6666 title="normal, font-feature-settings"><strong>6.12</strong></a>
jdaggett@8278 6667
jdaggett@8278 6668 <li>font-kerning, <a href="#font-kerning-normal-value" title="normal,
jdaggett@8278 6669 font-kerning"><strong>6.3</strong></a>
jdaggett@8278 6670
jdaggett@8278 6671 <li>font-language-override, <a
jdaggett@8278 6672 href="#font-language-override-normal-value" title="normal,
jdaggett@8278 6673 font-language-override"><strong>6.13</strong></a>
jdaggett@8278 6674
jdaggett@8278 6675 <li>font-stretch, <a href="#font-stretch-normal-value" title="normal,
jdaggett@8278 6676 font-stretch"><strong>3.3</strong></a>
jdaggett@8278 6677
jdaggett@8278 6678 <li>font-style, <a href="#font-style-normal-value" title="normal,
jdaggett@8278 6679 font-style"><strong>3.4</strong></a>
jdaggett@8278 6680
jdaggett@8278 6681 <li>font-variant, <a href="#font-variant-normal-value" title="normal,
jdaggett@8278 6682 font-variant"><strong>6.11</strong></a>
jdaggett@8278 6683
jdaggett@8278 6684 <li>font-variant-alternates, <a
jdaggett@8278 6685 href="#font-variant-alternates-normal-value" title="normal,
jdaggett@8278 6686 font-variant-alternates"><strong>6.8</strong></a>
jdaggett@8278 6687
jdaggett@8278 6688 <li>font-variant-caps, <a href="#font-variant-caps-normal-value"
jdaggett@8278 6689 title="normal, font-variant-caps"><strong>6.6</strong></a>
jdaggett@8278 6690
jdaggett@8278 6691 <li>font-variant-east-asian, <a
jdaggett@8278 6692 href="#font-variant-east-asian-normal-value" title="normal,
jdaggett@8278 6693 font-variant-east-asian"><strong>6.10</strong></a>
jdaggett@8278 6694
jdaggett@8278 6695 <li>font-variant-ligatures, <a
jdaggett@8278 6696 href="#font-variant-ligatures-normal-value" title="normal,
jdaggett@8278 6697 font-variant-ligatures"><strong>6.4</strong></a>
jdaggett@8278 6698
jdaggett@8278 6699 <li>font-variant-numeric, <a href="#font-variant-numeric-normal-value"
jdaggett@8278 6700 title="normal, font-variant-numeric"><strong>6.7</strong></a>
jdaggett@8278 6701
jdaggett@8368 6702 <li>font-variant-position, <a href="#font-variant-position-normal-value"
jdaggett@8368 6703 title="normal, font-variant-position"><strong>6.5</strong></a>
jdaggett@8368 6704
jdaggett@8278 6705 <li>font-weight, <a href="#font-weight-normal-value" title="normal,
jdaggett@8278 6706 font-weight"><strong>3.2</strong></a>
jdaggett@8278 6707 </ul>
jdaggett@8278 6708
jdaggett@8278 6709 <li>oblique, <a href="#oblique" title=oblique><strong>3.4</strong></a>
jdaggett@5809 6710
jdaggett@1662 6711 <li>oldstyle-nums, <a href="#oldstyle-nums"
jdaggett@2118 6712 title=oldstyle-nums><strong>6.7</strong></a>
jdaggett@2118 6713
jdaggett@3638 6714 <li>ordinal, <a href="#ordinal" title=ordinal><strong>6.7</strong></a>
jdaggett@3638 6715
jdaggett@8225 6716 <li>ornaments, <a href="#ornaments"
jdaggett@7060 6717 title=ornaments><strong>6.8</strong></a>
jdaggett@2118 6718
jdaggett@1662 6719 <li>petite-caps, <a href="#petite-caps"
jdaggett@2118 6720 title=petite-caps><strong>6.6</strong></a>
jdaggett@1662 6721
jdaggett@1662 6722 <li>proportional-nums, <a href="#proportional-nums"
jdaggett@2118 6723 title=proportional-nums><strong>6.7</strong></a>
jdaggett@1662 6724
jdaggett@1662 6725 <li>proportional-width, <a href="#proportional-width"
jdaggett@2118 6726 title=proportional-width><strong>6.10</strong></a>
jdaggett@512 6727
jdaggett@7243 6728 <li>renderer, <a href="#renderer" title=renderer><strong>#</strong></a>
jdaggett@7103 6729
jdaggett@3638 6730 <li>ruby, <a href="#ruby" title=ruby><strong>6.10</strong></a>
jdaggett@1662 6731
jdaggett@890 6732 <li>sans-serif, definition of, <a href="#sans-serif0" title="sans-serif,
jdaggett@890 6733 definition of"><strong>#</strong></a>
jdaggett@890 6734
jdaggett@8278 6735 <li>semi-condensed, <a href="#semi-condensed-"
jdaggett@8278 6736 title=semi-condensed><strong>3.3</strong></a>
jdaggett@8278 6737
jdaggett@8278 6738 <li>semi-expanded, <a href="#semi-expanded"
jdaggett@8278 6739 title=semi-expanded><strong>3.3</strong></a>
jdaggett@8278 6740
jdaggett@890 6741 <li>serif, definition of, <a href="#serif0" title="serif, definition
jdaggett@890 6742 of"><strong>#</strong></a>
jdaggett@890 6743
jdaggett@2504 6744 <li>simplified, <a href="#simplified"
jdaggett@2504 6745 title=simplified><strong>6.10</strong></a>
jdaggett@1662 6746
jdaggett@1662 6747 <li>slashed-zero, <a href="#slashed-zero"
jdaggett@2118 6748 title=slashed-zero><strong>6.7</strong></a>
jdaggett@1662 6749
jdaggett@1662 6750 <li>small-caps, <a href="#small-caps"
jdaggett@2118 6751 title=small-caps><strong>6.6</strong></a>
jdaggett@1662 6752
jdaggett@1662 6753 <li>src, <a href="#descdef-src" title=src><strong>4.3</strong></a>
jdaggett@1662 6754
jdaggett@1662 6755 <li>stacked-fractions, <a href="#stacked-fractions"
jdaggett@2118 6756 title=stacked-fractions><strong>6.7</strong></a>
jdaggett@2118 6757
jdaggett@7103 6758 <li>style sheet
jdaggett@7103 6759 <ul>
jdaggett@7103 6760 <li>as conformance class, <a href="#style-sheet" title="style sheet, as
jdaggett@7243 6761 conformance class"><strong>#</strong></a>
jdaggett@7103 6762 </ul>
jdaggett@7103 6763
jdaggett@8225 6764 <li>styleset, <a href="#styleset" title=styleset><strong>6.8</strong></a>
jdaggett@8225 6765
jdaggett@8225 6766 <li>stylistic, <a href="#stylistic"
jdaggett@7060 6767 title=stylistic><strong>6.8</strong></a>
jdaggett@7060 6768
jdaggett@8279 6769 <li>sub, <a href="#sub" title=sub><strong>6.5</strong></a>
jdaggett@8279 6770
jdaggett@8279 6771 <li>super, <a href="#super" title=super><strong>6.5</strong></a>
jdaggett@8279 6772
jdaggett@8397 6773 <li>support, <a href="#support" title=support><strong>5.2</strong></a>
jdaggett@8397 6774
jdaggett@8225 6775 <li>swash, <a href="#swash" title=swash><strong>6.8</strong></a>
jdaggett@1662 6776
jdaggett@8363 6777 <li>system font fallback, <a href="#system-font-fallback" title="system
jdaggett@8363 6778 font fallback"><strong>5.2</strong></a>
jdaggett@8363 6779
jdaggett@1662 6780 <li>tabular-nums, <a href="#tabular-nums"
jdaggett@2118 6781 title=tabular-nums><strong>6.7</strong></a>
jdaggett@1662 6782
jdaggett@1662 6783 <li>titling-caps, <a href="#titling-caps"
jdaggett@2118 6784 title=titling-caps><strong>6.6</strong></a>
jdaggett@1856 6785
jdaggett@2504 6786 <li>traditional, <a href="#traditional"
jdaggett@2504 6787 title=traditional><strong>6.10</strong></a>
jdaggett@2118 6788
jdaggett@8278 6789 <li>ultra-condensed, <a href="#ultra-condensed"
jdaggett@8278 6790 title=ultra-condensed><strong>3.3</strong></a>
jdaggett@8278 6791
jdaggett@8278 6792 <li>ultra-expanded, <a href="#ultra-expanded"
jdaggett@8278 6793 title=ultra-expanded><strong>3.3</strong></a>
jdaggett@8278 6794
jdaggett@2118 6795 <li>unicase, <a href="#unicase" title=unicase><strong>6.6</strong></a>
jdaggett@1662 6796
jdaggett@1662 6797 <li>unicode-range, <a href="#descdef-unicode-range"
jdaggett@890 6798 title=unicode-range><strong>4.5</strong></a>
jdaggett@7311 6799
jdaggett@7311 6800 <li>weight, <a href="#weight" title=weight><strong>2</strong></a>
jdaggett@7311 6801
jdaggett@7311 6802 <li>width, <a href="#width" title=width><strong>2</strong></a>
jdaggett@484 6803 </ul>
jdaggett@484 6804 <!--end-index-->
jdaggett@484 6805
jdaggett@484 6806 <h2 class=no-num id=property-index>Property index</h2>
jdaggett@890 6807 <!--begin-properties-->
jdaggett@484 6808
jdaggett@484 6809 <table class=proptable>
jdaggett@484 6810 <thead>
jdaggett@484 6811 <tr>
jdaggett@484 6812 <th>Property
jdaggett@484 6813
jdaggett@484 6814 <th>Values
jdaggett@484 6815
jdaggett@484 6816 <th>Initial
jdaggett@484 6817
jdaggett@1148 6818 <th>Applies to
jdaggett@484 6819
jdaggett@484 6820 <th>Inh.
jdaggett@484 6821
jdaggett@484 6822 <th>Percentages
jdaggett@484 6823
jdaggett@484 6824 <th>Media
jdaggett@484 6825
jdaggett@484 6826 <tbody>
jdaggett@3460 6827 <tr>
jdaggett@3460 6828 <th><a class=property href="#propdef-font">font</a>
jdaggett@484 6829
jdaggett@8225 6830 <td>[ [ &lt;‘font-style’&gt; || &lt;font-variant-css21&gt; ||
jdaggett@8225 6831 &lt;‘font-weight’&gt; || &lt;‘font-stretch’ ]?
jdaggett@8225 6832 &lt;‘font-size’&gt; [ / &lt;‘line-height’&gt; ]?
jdaggett@8225 6833 &lt;‘font-family’&gt; ] | caption | icon | menu | message-box |
jdaggett@7020 6834 small-caption | status-bar
jdaggett@484 6835
jdaggett@484 6836 <td>see individual properties
jdaggett@484 6837
jdaggett@484 6838 <td>all elements
jdaggett@484 6839
jdaggett@484 6840 <td>yes
jdaggett@484 6841
jdaggett@484 6842 <td>see individual properties
jdaggett@484 6843
jdaggett@484 6844 <td>visual
jdaggett@484 6845
jdaggett@3460 6846 <tr>
jdaggett@8278 6847 <th><span class=property>font-family</span>
jdaggett@484 6848
jdaggett@8225 6849 <td>[ &lt;family-name&gt; | &lt;generic-family&gt; ] #
jdaggett@484 6850
jdaggett@484 6851 <td>depends on user agent
jdaggett@484 6852
jdaggett@484 6853 <td>all elements
jdaggett@484 6854
jdaggett@484 6855 <td>yes
jdaggett@484 6856
jdaggett@484 6857 <td>N/A
jdaggett@484 6858
jdaggett@484 6859 <td>visual
jdaggett@484 6860
jdaggett@3460 6861 <tr>
jdaggett@8279 6862 <th><span class=property>font-feature-settings</span>
jdaggett@1662 6863
jdaggett@8225 6864 <td>normal | &lt;feature-tag-value&gt; #
jdaggett@1662 6865
jdaggett@1662 6866 <td>normal
jdaggett@1662 6867
jdaggett@1662 6868 <td>all elements
jdaggett@1662 6869
jdaggett@1662 6870 <td>yes
jdaggett@1662 6871
jdaggett@1662 6872 <td>N/A
jdaggett@1662 6873
jdaggett@1662 6874 <td>visual
jdaggett@1662 6875
jdaggett@3460 6876 <tr>
jdaggett@3460 6877 <th><a class=property href="#propdef-font-kerning">font-kerning</a>
jdaggett@1662 6878
jdaggett@1856 6879 <td>auto | normal | none
jdaggett@1856 6880
jdaggett@1856 6881 <td>auto
jdaggett@1662 6882
jdaggett@1662 6883 <td>all elements
jdaggett@1662 6884
jdaggett@1662 6885 <td>yes
jdaggett@1662 6886
jdaggett@1662 6887 <td>N/A
jdaggett@1662 6888
jdaggett@1662 6889 <td>visual
jdaggett@1662 6890
jdaggett@3460 6891 <tr>
jdaggett@3460 6892 <th><a class=property
jdaggett@1732 6893 href="#propdef-font-language-override">font-language-override</a>
jdaggett@1662 6894
jdaggett@5809 6895 <td>normal | &lt;string&gt;
jdaggett@1662 6896
jdaggett@1662 6897 <td>normal
jdaggett@1662 6898
jdaggett@1662 6899 <td>all elements
jdaggett@1662 6900
jdaggett@1662 6901 <td>yes
jdaggett@1662 6902
jdaggett@1662 6903 <td>N/A
jdaggett@1662 6904
jdaggett@1662 6905 <td>visual
jdaggett@1662 6906
jdaggett@3460 6907 <tr>
jdaggett@3460 6908 <th><a class=property href="#propdef-font-size">font-size</a>
jdaggett@484 6909
jdaggett@8225 6910 <td>&lt;absolute-size&gt; | &lt;relative-size&gt; | &lt;length&gt; |
jdaggett@8225 6911 &lt;percentage&gt;
jdaggett@484 6912
jdaggett@484 6913 <td>medium
jdaggett@484 6914
jdaggett@484 6915 <td>all elements
jdaggett@484 6916
jdaggett@484 6917 <td>yes
jdaggett@484 6918
jdaggett@484 6919 <td>refer to parent element's font size
jdaggett@484 6920
jdaggett@484 6921 <td>visual
jdaggett@484 6922
jdaggett@3460 6923 <tr>
jdaggett@3460 6924 <th><a class=property
jdaggett@1662 6925 href="#propdef-font-size-adjust">font-size-adjust</a>
jdaggett@484 6926
jdaggett@8225 6927 <td>none | auto | &lt;number&gt;
jdaggett@484 6928
jdaggett@484 6929 <td>none
jdaggett@484 6930
jdaggett@484 6931 <td>all elements
jdaggett@484 6932
jdaggett@484 6933 <td>yes
jdaggett@484 6934
jdaggett@554 6935 <td>N/A
jdaggett@484 6936
jdaggett@484 6937 <td>visual
jdaggett@484 6938
jdaggett@3460 6939 <tr>
jdaggett@8278 6940 <th><span class=property>font-stretch</span>
jdaggett@1662 6941
jdaggett@1662 6942 <td>normal | ultra-condensed | extra-condensed | condensed |
jdaggett@1662 6943 semi-condensed | semi-expanded | expanded | extra-expanded |
jdaggett@5809 6944 ultra-expanded
jdaggett@484 6945
jdaggett@484 6946 <td>normal
jdaggett@484 6947
jdaggett@484 6948 <td>all elements
jdaggett@484 6949
jdaggett@484 6950 <td>yes
jdaggett@484 6951
jdaggett@484 6952 <td>N/A
jdaggett@484 6953
jdaggett@484 6954 <td>visual
jdaggett@484 6955
jdaggett@3460 6956 <tr>
jdaggett@8278 6957 <th><span class=property>font-style</span>
jdaggett@484 6958
jdaggett@5809 6959 <td>normal | italic | oblique
jdaggett@484 6960
jdaggett@484 6961 <td>normal
jdaggett@484 6962
jdaggett@484 6963 <td>all elements
jdaggett@484 6964
jdaggett@484 6965 <td>yes
jdaggett@484 6966
jdaggett@484 6967 <td>N/A
jdaggett@484 6968
jdaggett@484 6969 <td>visual
jdaggett@484 6970
jdaggett@3460 6971 <tr>
jdaggett@3460 6972 <th><a class=property href="#propdef-font-synthesis">font-synthesis</a>
jdaggett@2487 6973
jdaggett@2487 6974 <td>none | [ weight || style ]
jdaggett@2487 6975
jdaggett@2487 6976 <td>weight style
jdaggett@2457 6977
jdaggett@2457 6978 <td>all elements
jdaggett@2457 6979
jdaggett@2457 6980 <td>yes
jdaggett@2457 6981
jdaggett@2457 6982 <td>N/A
jdaggett@2457 6983
jdaggett@2457 6984 <td>visual
jdaggett@2457 6985
jdaggett@3460 6986 <tr>
jdaggett@8278 6987 <th><span class=property>font-variant</span>
jdaggett@1662 6988
jdaggett@6436 6989 <td>normal | none | [ &lt;common-lig-values&gt; ||
jdaggett@3460 6990 &lt;discretionary-lig-values&gt; || &lt;historical-lig-values&gt; ||
jdaggett@3041 6991 &lt;contextual-alt-values&gt; || stylistic(&lt;feature-value-name&gt;)
jdaggett@8225 6992 || historical-forms || styleset(&lt;feature-value-name&gt; #) ||
jdaggett@8225 6993 character-variant(&lt;feature-value-name&gt; #) ||
jdaggett@5833 6994 swash(&lt;feature-value-name&gt;) ||
jdaggett@3041 6995 ornaments(&lt;feature-value-name&gt;) ||
jdaggett@4545 6996 annotation(&lt;feature-value-name&gt;) || [ small-caps | all-small-caps
jdaggett@6648 6997 | petite-caps | all-petite-caps | unicase | titling-caps ] ||
jdaggett@2509 6998 &lt;numeric-figure-values&gt; || &lt;numeric-spacing-values&gt; ||
jdaggett@3638 6999 &lt;numeric-fraction-values&gt; || ordinal || slashed-zero ||
jdaggett@3638 7000 &lt;east-asian-variant-values&gt; || &lt;east-asian-width-values&gt; ||
jdaggett@3638 7001 ruby ]
jdaggett@484 7002
jdaggett@484 7003 <td>normal
jdaggett@484 7004
jdaggett@484 7005 <td>all elements
jdaggett@484 7006
jdaggett@484 7007 <td>yes
jdaggett@484 7008
jdaggett@7377 7009 <td>see individual properties
jdaggett@484 7010
jdaggett@484 7011 <td>visual
jdaggett@484 7012
jdaggett@3460 7013 <tr>
jdaggett@3460 7014 <th><a class=property
jdaggett@1662 7015 href="#propdef-font-variant-alternates">font-variant-alternates</a>
jdaggett@1662 7016
jdaggett@6176 7017 <td>normal | [ stylistic(&lt;feature-value-name&gt;) || historical-forms
jdaggett@8225 7018 || styleset(&lt;feature-value-name&gt; #) ||
jdaggett@8225 7019 character-variant(&lt;feature-value-name&gt; #) ||
jdaggett@5833 7020 swash(&lt;feature-value-name&gt;) ||
jdaggett@3638 7021 ornaments(&lt;feature-value-name&gt;) ||
jdaggett@3638 7022 annotation(&lt;feature-value-name&gt;) ]
jdaggett@1662 7023
jdaggett@1662 7024 <td>normal
jdaggett@1662 7025
jdaggett@1662 7026 <td>all elements
jdaggett@1662 7027
jdaggett@1662 7028 <td>yes
jdaggett@1662 7029
jdaggett@1662 7030 <td>N/A
jdaggett@1662 7031
jdaggett@1662 7032 <td>visual
jdaggett@1662 7033
jdaggett@3460 7034 <tr>
jdaggett@3460 7035 <th><a class=property
jdaggett@1662 7036 href="#propdef-font-variant-caps">font-variant-caps</a>
jdaggett@1662 7037
jdaggett@5809 7038 <td>normal | small-caps | all-small-caps | petite-caps | all-petite-caps
jdaggett@6648 7039 | unicase | titling-caps
jdaggett@1662 7040
jdaggett@1662 7041 <td>normal
jdaggett@1662 7042
jdaggett@1662 7043 <td>all elements
jdaggett@1662 7044
jdaggett@1662 7045 <td>yes
jdaggett@1662 7046
jdaggett@1662 7047 <td>N/A
jdaggett@1662 7048
jdaggett@1662 7049 <td>visual
jdaggett@1662 7050
jdaggett@3460 7051 <tr>
jdaggett@3460 7052 <th><a class=property
jdaggett@1662 7053 href="#propdef-font-variant-east-asian">font-variant-east-asian</a>
jdaggett@1662 7054
jdaggett@5809 7055 <td>normal | [ &lt;east-asian-variant-values&gt; ||
jdaggett@3638 7056 &lt;east-asian-width-values&gt; || ruby ]
jdaggett@1662 7057
jdaggett@1662 7058 <td>normal
jdaggett@1662 7059
jdaggett@1662 7060 <td>all elements
jdaggett@1662 7061
jdaggett@1662 7062 <td>yes
jdaggett@1662 7063
jdaggett@1662 7064 <td>N/A
jdaggett@1662 7065
jdaggett@1662 7066 <td>visual
jdaggett@1662 7067
jdaggett@3460 7068 <tr>
jdaggett@3460 7069 <th><a class=property
jdaggett@1662 7070 href="#propdef-font-variant-ligatures">font-variant-ligatures</a>
jdaggett@1662 7071
jdaggett@8225 7072 <td>normal | none | [ &lt;common-lig-values&gt; ||
jdaggett@8225 7073 &lt;discretionary-lig-values&gt; || &lt;historical-lig-values&gt; ||
jdaggett@8225 7074 &lt;contextual-alt-values&gt; ]
jdaggett@1662 7075
jdaggett@1662 7076 <td>normal
jdaggett@1662 7077
jdaggett@1662 7078 <td>all elements
jdaggett@1662 7079
jdaggett@1662 7080 <td>yes
jdaggett@1662 7081
jdaggett@1662 7082 <td>N/A
jdaggett@1662 7083
jdaggett@1662 7084 <td>visual
jdaggett@1662 7085
jdaggett@3460 7086 <tr>
jdaggett@3460 7087 <th><a class=property
jdaggett@1662 7088 href="#propdef-font-variant-numeric">font-variant-numeric</a>
jdaggett@1662 7089
jdaggett@5809 7090 <td>normal | [ &lt;numeric-figure-values&gt; ||
jdaggett@1732 7091 &lt;numeric-spacing-values&gt; || &lt;numeric-fraction-values&gt; ||
jdaggett@3638 7092 ordinal || slashed-zero ]
jdaggett@1662 7093
jdaggett@1662 7094 <td>normal
jdaggett@1662 7095
jdaggett@1662 7096 <td>all elements
jdaggett@1662 7097
jdaggett@1662 7098 <td>yes
jdaggett@1662 7099
jdaggett@1662 7100 <td>N/A
jdaggett@1662 7101
jdaggett@1662 7102 <td>visual
jdaggett@1662 7103
jdaggett@3460 7104 <tr>
jdaggett@3460 7105 <th><a class=property
jdaggett@3460 7106 href="#propdef-font-variant-position">font-variant-position</a>
jdaggett@3460 7107
jdaggett@3638 7108 <td>normal | sub | super
jdaggett@3460 7109
jdaggett@3460 7110 <td>normal
jdaggett@3460 7111
jdaggett@3460 7112 <td>all elements
jdaggett@3460 7113
jdaggett@3460 7114 <td>yes
jdaggett@3460 7115
jdaggett@3460 7116 <td>N/A
jdaggett@3460 7117
jdaggett@3460 7118 <td>visual
jdaggett@3460 7119
jdaggett@3460 7120 <tr>
jdaggett@8278 7121 <th><span class=property>font-weight</span>
jdaggett@484 7122
jdaggett@484 7123 <td>normal | bold | bolder | lighter | 100 | 200 | 300 | 400 | 500 | 600
jdaggett@5809 7124 | 700 | 800 | 900
jdaggett@484 7125
jdaggett@484 7126 <td>normal
jdaggett@484 7127
jdaggett@484 7128 <td>all elements
jdaggett@484 7129
jdaggett@484 7130 <td>yes
jdaggett@484 7131
jdaggett@484 7132 <td>N/A
jdaggett@484 7133
jdaggett@484 7134 <td>visual
jdaggett@484 7135 </table>
jdaggett@890 7136 <!--end-properties-->
jdaggett@5596 7137 <!--begin-descriptors-->
jdaggett@5596 7138
jdaggett@5596 7139 <table class=proptable>
jdaggett@5596 7140 <thead>
jdaggett@5596 7141 <tr>
jdaggett@5596 7142 <th>Descriptor
jdaggett@5596 7143
jdaggett@5596 7144 <th>Value
jdaggett@5596 7145
jdaggett@5596 7146 <th>Initial
jdaggett@5596 7147
jdaggett@5596 7148 <th>Percentages
jdaggett@5596 7149
jdaggett@5596 7150 <th>Media
jdaggett@5596 7151
jdaggett@5596 7152 <tbody>
jdaggett@5596 7153 <tr>
jdaggett@8278 7154 <th><span class=property>font-family</span>
jdaggett@5596 7155
jdaggett@8225 7156 <td>&lt;family-name&gt;
jdaggett@5596 7157
jdaggett@5596 7158 <td>N/A
jdaggett@5596 7159
jdaggett@5596 7160 <tr>
jdaggett@8279 7161 <th><span class=property>font-feature-settings</span>
jdaggett@5596 7162
jdaggett@8225 7163 <td>normal | &lt;feature-tag-value&gt; #
jdaggett@5596 7164
jdaggett@5596 7165 <td>normal
jdaggett@5596 7166
jdaggett@5596 7167 <tr>
jdaggett@8278 7168 <th><span class=property>font-stretch</span>
jdaggett@5596 7169
jdaggett@5596 7170 <td>normal | ultra-condensed | extra-condensed | condensed |
jdaggett@5596 7171 semi-condensed | semi-expanded | expanded | extra-expanded |
jdaggett@5596 7172 ultra-expanded
jdaggett@5596 7173
jdaggett@5596 7174 <td>normal
jdaggett@5596 7175
jdaggett@5596 7176 <tr>
jdaggett@8278 7177 <th><span class=property>font-style</span>
jdaggett@5596 7178
jdaggett@5596 7179 <td>normal | italic | oblique
jdaggett@5596 7180
jdaggett@5596 7181 <td>normal
jdaggett@5596 7182
jdaggett@5596 7183 <tr>
jdaggett@8278 7184 <th><span class=property>font-variant</span>
jdaggett@5596 7185
jdaggett@8225 7186 <td>normal | none | [ &lt;common-lig-values&gt; ||
jdaggett@5596 7187 &lt;discretionary-lig-values&gt; || &lt;historical-lig-values&gt; ||
jdaggett@5596 7188 &lt;contextual-alt-values&gt; || stylistic(&lt;feature-value-name&gt;)
jdaggett@8225 7189 || historical-forms || styleset(&lt;feature-value-name&gt; #) ||
jdaggett@8225 7190 character-variant(&lt;feature-value-name&gt; #) ||
jdaggett@5833 7191 swash(&lt;feature-value-name&gt;) ||
jdaggett@5596 7192 ornaments(&lt;feature-value-name&gt;) ||
jdaggett@5596 7193 annotation(&lt;feature-value-name&gt;) || [ small-caps | all-small-caps
jdaggett@6648 7194 | petite-caps | all-petite-caps | unicase | titling-caps ] ||
jdaggett@5596 7195 &lt;numeric-figure-values&gt; || &lt;numeric-spacing-values&gt; ||
jdaggett@5596 7196 &lt;numeric-fraction-values&gt; || ordinal || slashed-zero ||
jdaggett@5596 7197 &lt;east-asian-variant-values&gt; || &lt;east-asian-width-values&gt; ||
jdaggett@5596 7198 ruby ]
jdaggett@5596 7199
jdaggett@5596 7200 <td>normal
jdaggett@5596 7201
jdaggett@5596 7202 <tr>
jdaggett@8278 7203 <th><span class=property>font-weight</span>
jdaggett@5596 7204
jdaggett@5596 7205 <td>normal | bold | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900
jdaggett@5596 7206
jdaggett@5596 7207 <td>normal
jdaggett@5596 7208
jdaggett@5596 7209 <tr>
jdaggett@5596 7210 <th><a class=property href="#descdef-src">src</a>
jdaggett@5596 7211
jdaggett@8225 7212 <td>[ &lt;url> [format(&lt;string> #)]? | &lt;font-face-name&gt; ] #
jdaggett@5596 7213
jdaggett@5596 7214 <td>N/A
jdaggett@5596 7215
jdaggett@5596 7216 <tr>
jdaggett@5596 7217 <th><a class=property href="#descdef-unicode-range">unicode-range</a>
jdaggett@5596 7218
jdaggett@8225 7219 <td>&lt;urange&gt; #
jdaggett@5596 7220
jdaggett@5596 7221 <td>U+0-10FFFF
jdaggett@5596 7222 </table>
jdaggett@5596 7223 <!--end-descriptors-->
jdaggett@6648 7224 <script type="text/javascript">
jdaggett@6648 7225 window.onload = function () {
jdaggett@6648 7226 if (!("devicePixelRatio" in window && window.devicePixelRatio > 1)) return;
jdaggett@6648 7227 var i, hiresElements = document.getElementsByClassName("hires");
jdaggett@6648 7228 for (i = 0; i < hiresElements.length; i++) {
jdaggett@6648 7229 var h = hiresElements[i];
jdaggett@6648 7230 if (h.tagName != "IMG") continue;
jdaggett@6648 7231 var src = h.getAttribute("src");
jdaggett@6648 7232 var src2x = src.replace(/\.\w+$/, function(m) { return "@2x" + m; });
jdaggett@6648 7233 h.src = src2x;
jdaggett@6648 7234 }
jdaggett@6648 7235 }
jdaggett@6648 7236 </script>
jdaggett@484 7237 </html>
jdaggett@484 7238 <!-- Keep this comment at the end of the file
jdaggett@484 7239 Local variables:
jdaggett@484 7240 mode: sgml
jdaggett@484 7241 sgml-declaration:"~/SGML/HTML4.decl"
jdaggett@484 7242 sgml-default-doctype-name:"html"
jdaggett@484 7243 sgml-minimize-attributes:t
jdaggett@484 7244 sgml-nofill-elements:("pre" "style" "br")
jdaggett@484 7245 sgml-live-element-indicator:t
jdaggett@484 7246 sgml-omittag:nil
jdaggett@484 7247 sgml-shorttag:nil
jdaggett@484 7248 sgml-namecase-general:t
jdaggett@484 7249 sgml-general-insert-case:lower
jdaggett@484 7250 sgml-always-quote-attributes:t
jdaggett@484 7251 sgml-indent-step:nil
jdaggett@484 7252 sgml-indent-data:t
jdaggett@484 7253 sgml-parent-document:nil
jdaggett@484 7254 sgml-exposed-tags:nil
jdaggett@484 7255 sgml-local-catalogs:nil
jdaggett@484 7256 sgml-local-ecat-files:nil
jdaggett@484 7257 End:
jdaggett@484 7258 -->
jdaggett@8277 7259 <!--
jdaggett@1856 7260
jdaggett@1856 7261 to do:
jdaggett@1856 7262
jdaggett@1856 7263 - wording of OpenType family name handling
jdaggett@1856 7264 - handling combining sequences in the font matching algorithm
jdaggett@1856 7265 - fix-up fi ligature example
jdaggett@1856 7266
jdaggett@1856 7267 -->

mercurial